what are good realistic materials to buy to prepare for

[susanring]

there are too many materials out there.
what do I buy.

for strong fundamentals and questions that are close to the real exams
?
what else? how do I prepare for it?

[VP_Jim]

The best practice questions are in the Official Guide(s). There is a big orange book that contains math and verbal, and smaller green and purple books that contain math and verbal alone. These books contain thousands of actual old GMAT questions, so they are excellent practice for the test.

Happy studying!

[lunarpower]

the official guides are definitely the best way to go.

for "fundamentals", though, you may also want to consider our MGMAT strategy guides. (they're interestingly named - "strategy guides" even though their content could be more aptly described as content than as strategy.)
those guides will help you learn - or re-learn, as the case may be - the fundamentals behind the official problems.
there are 8 of them, each for its own separate topic (5 different math topics - geometry, word translations, number properties, fractions/decimals/percents, and algebra/equations/inequalities - and 3 different verbal topics - SC, CR, and RC).