I used:
* OCA
Java SE 7 Programmer I Study Guide (Exam 1Z0-803) (Oracle Press) // Though there are some errors in the book, but it's okay
* Kaplan Self
Test: 1Z0-803: Java SE 7 Programmer I // Bought the 30 day version, I felt it was worth it
* Practice Test: JA+ V7 for Oracle Certified Associate - Java SE7 Programmer I - From: EnthuWare // Well worth the $9.95
If you can pass the EnthuWare practice tests,
you should pass the exam.