I took the GRE in 2010. It was fairly similar to the SATs, except I found the verbal section to be more advanced. It has been revised once since I took the exam. When I took the exam, the verbal was focused on vocabulary, but now it has more emphasis on reading comprehension.

Studying and practice tests are definitely very useful. I improved my score a lot by going through a practice book. Most of the material isn't extremely difficult - but I hadn't thought about a lot of it since high school. Best wishes .