I came across a website (islamcomicbook.com) which gives a nice brief and entertaining introduction to some of the absurdities in Islam in cartoon format with references to the Hadiths and Koran. My suggestion would be that you go read the comic as it gives you some ammunition which you can point to when debating Muslims. Although, I would suggest more detailed research before you take on most Muslims in a debate. As a side note here, and this is a big kudos to Muslims. Most Muslims really do know their holy texts compared to multiple other religions. The fact that most Muslims misinterpret the Koran is another aspect all together.
Now, here is the more interesting part about this book and website for me. Its written by a Christian who somehow believes there religion is more logical than the Islam. In fact there is a whole section of the website devoted to why Christianity is the only way to heaven. Think about it, how can your goat herders be more accurate than another mans goat herders?
Regardless of these facts, the book is still a good introduction to the stupidity in Islam, and this website is a perfect example of the cognitive dissonance that occurs in multiple theists heads.