I suggest reading this book before the Oracle DBA 101 book. I liked this book. I thought is was very easy to read and well presented. I especially found the authors experiences and insights to be helpful. A very popular study guide to prepare for the Oracle DBA certifications.
Some people swear by it and some people swear at it.
It hard to say why the extreme differences in opinion, but I found it to be a useful companion to the Oracle ILT course books. All rights reserved.