Newbie query

I am currently studying for the Oracle 7 DBA track and am wondering about a few things:

• the best books to use as reference(some with exam prep questions)
• any news when and if any of the four core exams are to be retired
• any surplus Oracle Student Guides they use with their courseware would be appreciated since as a student there is no way I can afford the big bucks it costs for their Instructor Led Training! Thanks in advance!