Here’s a link to a fun site with lots of personality tests: SimilarMinds.Com. I’ve only checked out the Short Test under the Jung Tests category. But it correctly identified me as an ISTJ. It’s a good short version of Myers Briggs to get you started if you’ve never taken the test before. But I do recommend that you take the full test and have it administered by someone who can tell you what it all means.
Myers Briggs isn’t about what you are and what you aren’t. It’s about your preferences. At its best, it will help you understand more about yourself and your friends/family/colleagues/etc. so you can have better relationships.