You must have ample number of questions and topics for better practice and understanding. You can collect all stuff from:
Many books are available in the market for the preparation of GRE. The main disadvantage of book in the preparation is the lack of guidance in case of difficulties and the lack of quick methods because book follow teacher less methods.
The most modern and the most effective method is the online preparation with online teacher support. Many online institutions offer packages for effective preparation.
If candidate feel difficulty in self-study methods then he can join classroom courses offered by any reputed institution in the region.
The core of GRE is vocabulary. Applicant must have a large pool of standardized words.