There are some free download study tips and guide for the GRE. Here are the list.
1. ETS GRE PowerPrep 3.1
The Official GRE testing Software
2, Barrons How to Prepare for the GRE
3. Kaplan Guide
One of the most comprehensive study materials for the Graduate Record Examination.
4. Nova's GRE Prep Guide
Nova's GRE Prep Guide teaches proven techniques specifically designed to help students prepare for the computerized format of the Graduate Record Examination. Newly updated, this best-selling guide provides comprehensive preparation for the GRE.
5. GRE Issue Essay Samples
Sample Issue Essays for the Analytical Writing Section
6. Kaplan GRE Verbal Workbook
7. GRE Big Book
8. Barrons GRE Wordlist
Here's the link: http://greghost.blogspot.com/2006/09/free-gre-downloads_05.html