1) I know absolutely nothing about offset, or what it really is.

I want to get some new wheels for my car. I found a set of 18x8 wheels I want, and they are offered in +25, 33, 45, and 48 offset. How do I know which will fit or look best? I hear that the bigger the number the bigger the lip will be but I also want my wheels to fit/function/fit! lol thanks for the help