Prentice Hall, Oracle Forms
http://www.bookpool.com/.x/ifyab5j9ri/sm/0130158089

Prentice Hall, Oracle Developer/2000 Handbook (covers Reports too)
http://www.bookpool.com/.x/ifyab5j9ri/sm/0139490337

Prentice Hall (again), Oracle Forms Developer - The Complete Video Course (related to the first one)
http://www.bookpool.com/.x/ifyab5j9ri/sm/0130321249

Oracle Press books - get them only if you need heavyweight door stops