If this kind of stuff interests you, you should check out the lecture videos from Harvard's Stat 110: http://stat110.net. Prof. Blitzstein is hilariously nerdy but still has a very clear presentation style (he had kind of a cult following back when I took the course [1]). If video isn't your thing, the article here is basically the first few chapters of the textbook [2].

[1] http://www.youtube.com/watch?v=iAwS7vzvLnY http://www.youtube.com/watch?v=TQvVLhWOiis

[2] http://www.amazon.com/First-Course-Probability-7th-Edition/d...