I quick link to the JobHuntersBible site page on personal assessments, with a large variety of assessment tools.

This has a lot of good information, with personality tests, skills assessments, I've been looking around at a variety of pages, and this is one of the better ones.  I particularly like that the Myer's Brigg's personality assesssment test is mentioned.  For me, this was a pretty accurate tool, when I did the self-assessment.

the small "test and advice" commentary is well-done.  With a wry sense of humor, but practically grounded.

It's interesting to experiment with a couple of these.  You can get a good sense of common themes that come up for you,  again and again, with different tests.