• General GRE
• TOEFL IBT
This is just a recommendation because maybe your school require more exams or some different exams.
This is the main page of GRE: www.ets.org
Then you should click on the option of the GRE, and then in test takers.
There are two kinds of GRE:
I did the General GRE, so what I know the most is about the General GRE. You have to see in the page of the school you want to enter which GRE (General or Subject) are requiring for admissions. If you don't know which school are you going to, maybe you should do the General GRE because is required almost in all schools in US.
Inside of the page of the General GRE, you will find a lot of information of the GRE. To get an idea about the General GRE take a look of the POWERPREP.
To get the POWERPREP:
2. Test Takers
3. GRE Test Overview
4. GRE General Tests
4. About the Test
5. Download Library
In the page of ETS, you can find a section that tells you about material than can help you with the General GRE. You should take a look of the POWERPREP for the General GRE. Fill the page with your data, and then download the sample of the exam.
Some helpful pages: