I used Jaworski to study for SCJA. I also did a lot of my own research but only just scraped SCJA with 75%. SCJA is no longer available but has been replaced with
SCEA for J2EE. Jaworski would still be a good book to read as some of the topics he covers will be in the exam but you will not pass SCEA using this book due to the greater emphasis on J2EE technologies.
If you only have enough cash for one book then buy Richard Monson-Haefels book on EJB.
I read this book and passed SCEA part one with 79%