Contracts with roommates

[Kevin Paglia]

If things go well I might be making my first investment (ever the optimist, I am). This question is about renting out rooms to strangers: In a SFH situation what kind of contract do you draw up when renting out a room? Do you go all Sheldon (Big Bang reference) or something simpler? How do you do a background check on people in this situation? Really rather not do a Rental company yet, too soon with it being the first property.

Also how did you negotiate the utilities and such?

What Am I not thinking of?