You don't actually need a good grasp on probability theory to participate here
Anecdotally, the most strongly upvoted articles tend not to be specifically about math and statistics, but rather about meta-thinking issues: how insights from AI, cog sci, stats, social science and so on can help improve our thought processes.
Some research says that lurkers make up over 90% of online groups. I suspect that Less Wrong has an even higher percentage of lurkers than other online communities.
Please post a comment in this thread saying "Hi." You can say more if you want, but just posting "Hi" is good for a guaranteed free point of karma.
Also see the introduction thread.