What JKR Says about Her Characters.

Students at Hogwarts: Harry | Hermione | Ron | Neville | Other Hogwarts students

Staff at Hogwarts: Dumbledore | Hagrid | McGonagall | Snape | Lupin | Other professors | Ghosts

Other characters: Voldemort | Sirius Black | Peter Pettigrew | Godric Gryffindor

Families: Potters | Weasleys | Malfoys | Blacks | Dursleys

Organizations: Ministry of Magic | Order of the Phoenix | Death Eaters

Miscellaneous: Ancestry | Names | Relationships | Death

More summaries:
Characters | Places | Wizarding World | Books 1-7 | Jo |
Interviews of other people "in the know"