To give you an idea of what's been nominated so far, you can look at this list. Those that get the most nominations will get on the final ballot.
For the record, I've nominated Christopher Priest's The Islanders (Gollancz) in Best Novel. For Best Art I've nominated Anne Sudworth's cover of Liz Williams’ A Glass of Shadow. and in best non-fiction, I've nominated David Seed's Science Fiction: A Very Short Introduction, Mike Ashley's Out of This World: Science Fiction But Not As You Know It, and Adam Roberts' introduction to Justina Robson's Heliotrope.