Dont Rest Your Head is an rpg platform which is played in various places, including, now, here. I could explain it but frankly, theres already something for that. Its called a pdf. If you are having problems finding it, you should send me a pm...i might possibly unnoficialy be able to give it to you for free....possibly.

Other than that you will need a dice rolling program, which, seeing as it is freeware, i can definately give you. Voila.
http://www.asmor.com/programs/dicechucker/

Play well, stay sane, and dont fall asleep...