[Humabout]

With regard to magic, if you are strictly following Tolkein's ideas, magic (that isn't that of the Vala or Maya) is merely skill elevated to magical proportions. The elves' command of song and art has attained magical levels, as has the craftsmanship of the dwarves. The magic of the Wizards and that of Sauron himself is the magic of the Maya and Vala, and not something mortals really get to play with. The magic offered by the Rings represents power, temptation, and corruption, and may not be particularly suitable for PCs.

You might consider making schools of magic that represent the elvish and dwarvish arts. Each would require high levels of mundane skills, like singing, or smithing. The magic of the Rings might be represented by Spirit Assisted Magic, with the "personality" of each ring being the spirit in question, and granting free access to a range of related spells. The Ring should probably carry an addiction to rival that of heroin and be really, really nasty in general, god forbid you let your players touch that one - I'm thinking corruption and sanity rules from GURPS Horror here.