Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Good beginning or backup reference

I never feel safe having just one book around when I'm learning something . . . the broad coverage and low price convinced me to buy this as my "backup" to the main book I intended to learn from, but I ended up dumping the other one and using this one almost exclusively! The section on JavaBeans and JDBC, in particular, were very helpful, and much clearer than in other books I've tried.