though i am not interested in going abroad for studies as it is quite hard hittng on the pocket . I believe the education in our country is quite upto the mark and well competitive in any case but as for US education is concerned the best resource is
Study in the USA - Learn English here! ESL schools, English courses, universities, colleges, boarding schools, TOEFL info, and more!
GRE is basically when you want to do a post graduate course , plus for other graduate and diplomas , sat and toefl suffice .