Can you suggest the essential resources for GRE preparation?

You can also try Wiseswan - http://www.wiseswan.com/. It contains both Verbal and Quant practice tests. After taking the tests you can compare your performance with other test takers. This helps in identifying how exactly good is your approach to each question.

Hello friends i just came across a very interactive course on Probability for gre aspirants. This is a completely free video course. You just need to enroll using your id and password. I am sharing the link with you. Do enroll http://ufaber.com/course/probability-from-scratch-for-aptitude-exams-gmat-cat-gre-and-others/

I studied from Barron's myself. Also you need to develop English comprehension by reading English articles and literature from various sources. For Quant, just be clear with the basics and speed-solving techniques. I got 326 in 2011.

GET this on Android and  GRE vocab will be fun : https://play.google.com/store/apps/details?id=com.labfreaks.pixnary

For the vocabulary section you might want to take a look at http://apphttps://play.google.com/store/apps/details?id=com.something.grewords for android. It has resources for Barron's and Manhattan's word-lists and is very useful to remember and study words from important word-lists and can also be used as on-the-go flashcards.

Try these free resources: http://www.chiprime.com/static/home.html The second math resource is an adaptive quiz in Beta, with a ratchet function - correct answers lead to more difficult questions, while incorrect answers lead to simpler ones. And more questions are being added soon. You receive a score at the end of every quiz, and I have played this quiz several times even while commuting, on my smart-phone.

I used these resources in the following order to get a 165 in verbal. Maghoosh vocabulary flashcards- around a 1000 words. Barron's 1100 essential words for GRE Manhattan RC Guide ETS official guide for Verbal The last one was essential as the level of RCs that ETS has cannot be found anywhere else other than in there official guide. Manhattan RC guide is pretty spot on too. Be sure to practice these book at the very end of your verbal preparation as they have a limited number of questions. For quant I would suggest using only the official guide as it gives a comprehensive review of all the topics. Please avoid using any other resources. The type of questions you would see in the actual paper would only be found in their original guides. There are several other resources which would only deviate you and waste your time by making you practice either very easy questions ( to make you feel like you have improved) or very difficult questions ( to try and compel you to buy some of their resources). And be wary of free full length tests and other free verbal questions (widely available online) as they are designed to be tough and would make you lose your morale. Several of them had absurd answers too. Use only the 4 tests (2 paper and 2 online) practice tests provided by ETS.

I prepared for the GRE in less than a month and scored 325. I've written in detail about what should be your strategy if you want to prepare in less than a month in my blog. Link : https://alpharohit.wordpress.com/2015/06/20/prepare-for-the-gre-in-a-month/ I've listed down all the resources section wise in it.