Personality tests are a good tool to help you understand other people and where they are coming from, and perhaps more importantly, understanding yourself.
I took this test today and my result was INTJ: Introverted Intuitive Thinking Judging
There is a lot of truth to this testing; I found it to be quite enlightening! I encourage you to go take the test and see what you get, then google your type and see what else you can find.
If you are an INTJ, chime in! There are few of us in this world and we need to stick together! :)
One rather humorous site I found in relation to INTJ's is here (has some mild language): INTJ Central
If you're looking for basic stuff and not a lot of humor, there's this one: TypeLogic INTJ
I encourage you to take the quiz yourself and see what you get--you might be surprised at what you have to learn! :)