Below are the good good sql/plsql book.
Prepared By Manjunath BT : SQL BOOK
Prepared BY Tutorialspoint.com : SQL/PLSQL BOOK
If your new to SQL and PLSQL - Then go for this book : SQL/PLSQL
Prepared BY Tutorialspoint.com : SQL/PLSQL BOOK
If your new to SQL and PLSQL - Then go for this book : SQL/PLSQL