This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
That book just does not cover i*SQLPLUS. So, you need to download i*SQLPLUS guide from OTN. As long as you study and hands on practice. Whatever book you use, does not matter. I use 8i exam guide, cos my company only has this. New features in 9i, I look in OTN. SQL won't change much, just Oracle sqlplus command or function may would have new, example NVL2 in 9i.