"Every man has a desire for one type of work or business more than for any other...if his body is fit for it and he is able to endure its hardship, he should turn to it and choose it as the source for his income." - Chovos Halevavos

You might remember those words from earlier in the book. They're crucial, but how should we intelligently apply them? Just how is a young Jew to sift through all of the many "voices" he hears within and the countless possible careers he knows exist "out there"? He wants to travel the path chosen for him by G-d, but it seems hidden among so many others.
Here's where some kind of career counseling can be useful. Over the past decades, various testing techniques have been developed to help people understand their personal strengths and preferences and to direct them towards appropriate career choices. It may not be perfect, but testing is available and it's not that expensive (in fact, it's sometimes free).
And best of all: you've got very little to lose.

Limitations
Career testing (and career counseling in general) certainly isn't perfect. Here are some important ideas to bear in mind (largely drawn from material written by Dick Bolles, author of "What Color is your Parachute" - a venerable and successful book on the art and science of job hunting. More from him can be found here.
First of all, a psychological test is usually nothing more than a series of cleverly constructed questions designed to detect patterns. The test will try to assign you to one of a finite number of categories. But if you don't happen to fit in as expected or, sometimes, if you make even a single mistake in your responses, the results could be badly skewed. It would be bad enough if the resulting advice made no sense, but it can be tragic if the report you get seems to make sense but, in reality, was aimed at someone who exists only in the imagination of a counselor (or in the lines of code from some computer program). Just think about the impact such a mistake could have!
So how, then, should you approach career testing?
One, don't take it too seriously. Psychometric tests are an intelligent tool for making educated guesses, but they're not prophetic. The very best things such testing can provide are good, fresh suggestions for further investigation; indications of new, unexpected directions in which to look. At the very worst, you'll have spent an hour or two thinking about yourself.
Two, get a second opinion. And a third. Since there are a number of testing styles (more about that later), and since no two people will react the same way to any given test, it's worth your while to try a few tests built using diverse philosophical models. If all the results match up pretty consistently, then you're probably on to something.
Above all else, however, testing must inspire serious self-analysis. if the results prompt us to see things in creative new ways - opening doors to new possibilities - then they will have proven their worth.

Testing Categories
Besides the different philosophical approaches to creating career tests (leading to notably different methodology), there are also four completely different classes of tests (some of this information was drawn from an article accessed on the US Government web site)
"Interest inventories" employ the Holland Scale of interest types to assess a person's personal preferences. The kinds of things one enjoys doing in his spare time are likely the things at which he'll be the best (not that there are a lot of high paying jobs available for professional sleepers). A test might discover a useful link between spare-time pursuits and potential full-time work. Again, as we mentioned above, you are likely to do a better job if you enjoy the work and find it rewarding. Better job performance means a happier working life and greater opportunities for financial growth (not to mention a more honest effort on behalf of your employer or customer). "Work values instruments" list and prioritize the things you most want in a job (such as achievement, autonomy, recognition, support, and specific conditions of work). Your priorities can then be matched against a database of career choices for options that fit your profile.
"Personality measures" attempt to assess your personality type. It goes without saying that a shy and retiring individual isn't likely to excel working as a high-energy corporate lawyer and an ambitious, socially energized person will never fit well into the quiet lifestyle of a dairy rancher. The aim of these tests is to highlight your personality profile and match it with some suitable job prospects.
Aptitude tests assess a person's knowledge, skills and ability in order to identify jobs for which he is already professionally suited or for which a reasonable amount of additional training can prepare him. These tests could search for the kind of skills acquired through prior education, through work experiences or for a person's inborn or undeveloped talents.

Properly administered, a combination of tests from most or all of the above classes can be a powerful tool in focusing your attention on productive possibilities.

Where should you seek testing?
There are three main test site options.
Government employment centers often provide some level of vocational testing without charge. These offices should generally have the capability to link your results directly to data banks incorporating descriptions and projections for thousands of career options (an invaluable tool). Some Jewish communities also provide testing through their family services offices. There is often some charge for these tests.
Private assessment centers are in a position to offer the most comprehensive testing experiences along with fully personalized face to face counseling. Of course, the higher costs for such counseling will play a large role in deciding whether to take this route.
Online (Internet) testing is the most convenient and, usually, the cheapest alternative. It is true that interacting with a computer program can seem like a very impersonal and even cold experience - and there really is no replacement for good old-fashioned individualized human insight. But the low cost and easy accessibility of online testing make it easier to try different testing approaches. Bearing in mind that no assessment system is perfect, choosing carefully from the many online options might sometimes bring surprising success.

Online Testing Resources
Having been duly warned of their potential limitations, here is a list of some online programs (which, I should add, I haven't personally used):
US Government information hub for career and job interest exploration tools careeronestop.org. It's free, it's quite comprehensive, and, if the Federal Government is behind it, it's probably as close to state of the art as you can expect from such a program. Fully explore all the options that seem useful.
Careertest - $25 online aptitude test. Career Test claims to have been built on years of preparation and to produce a 99.5% success rate (although I'm not sure exactly how they measure "success" in this context).
This is a 71 question, 20 minute test that includes a sample report and five job descriptions for free. Their full report (presumably, presented with more job descriptions) can then be ordered for a fee. Uses the MAPP testing system.
The Highlands Ability Battery. Highlands seems to offer a more traditional and exhaustive testing experience (what they call "personal vision" testing) in combination with Internet availability (or, alternatively, through purchase of their CDRom version). The fee includes a two hour live consultation (either by phone or face to face with a local affiliate).
Analyzemycareer seems to offer the advantage of a larger cluster of seven different tests. The whole set costs $40.
Careerplanner's focus is, obviously, to promote their own service (which runs for less than $20), but they also offer useful comparisons of a selection of competing sites.

Other Testing Resources:
Government resources:
The US government's Career One Stop "find a service" site.
Call 1-877-US-2JOBS for information from the Career One Stop career center locator or see it online.
Government of Canada career search information: find a Human Resource Centre ("Human Resource Centre" is government-talk for "an office with stuff about jobs") .
In addition, Highlands Ability Battery, MBTI (Myers-Briggs Type Indicator), The Strong Inventory and True Colors are some of the better known traditional career testing programs.

Robert Lubin is a frum career counselor who is qualified and able to offer counseling over the Internet or face to face (he lives in Israel). You can contact him through his Linkedin page or via this site.

Important note. Before responding to newspaper ads or web sites, job hunters would be well advised to carefully investigate any company selling literature that's designed to help people gain access to well-paying and easily-available United States Federal Government or US Postal Service employment. The following alert comes from the web site of the US Federal Trade Commission - dated September, 2002:

Federal and postal job scams are among the biggest rackets on the employment front, preying on consumers who are unemployed or underemployed and who can least afford to be "taken."
...The Federal Trade Commission is taking steps toward protecting consumers against these scams. It's tracking down and putting the brakes on companies that make deceptive claims about the availability of federal and postal jobs, the procedures required to apply for those jobs, and the materials sold to help people identify and land those jobs.
...it's not necessary for consumers to pay for information about job vacancies with the U.S. government or the U.S. Postal Service. Federal agencies and the Postal Service never charge application fees, or guarantee that an applicant will be hired. And although the Postal Service requires applicants to take a test, it typically offers sample questions and study materials free to people who sign up for the exam.
...It's totally unnecessary for consumers to get conned into paying for something that's available for free.
...In addition,...it's deceptive for anyone to guarantee that a person will get any particular score on the postal entrance exams, or that a high score will guarantee them a job.
...Information on postal jobs is available at post offices...
Consumers also can find information about jobs with the Postal Service at www.usps.gov and jobs with the federal government at www.usajobs.opm.gov.