Here you can find some resources that can help you prepare with Brain Teasers. Remember the more you read the better prepared you will be.

Heard on the Street: Quantitative Questions from Wall Street Job Interviews: A famous book, that you can find as an ebook featuring famous brainteasers asked in interviews. Make  sure you have a read on that

Braingle: Great site with brain teasers

Brainden : Many brain puzzles to feast you brain with

Brainbashers : Brain teasers, puzzles and games for all brains

Sharpbrains : Countless brain teasers to make your brain smarter

Brainteasercentral : Another great site to find brainteasers