Take a look at
this post and
this thread from back when we first implemented RP points and the HP skill system. They should answer some of your questions, but if there's anything in particular you're still unsure about just ask! The only things that have changed since then are that we've fully implemented the spending of RP points to learn spells that are extra-curricular(aka, not covered in classwork), RP points are not required to year up(that idea was scrapped), and skill rolls use a d8 instead of a d20.