TLDR
To sign up, you need to provide the following data.
Character/s you would like to play as. (Or possibly ones you rather not play if you're generally open to most characters.)
Decide on Variant rules: (Read the rules on details regarding these)
Media Res: Yes or No
Lucky Bastards: Yes or No
Backstories: Yes or No
Anonymous Forum Accounts: Yes or No
And rules are found here.