I studied for all of my written exams by taking practice exams on the computer. There is a great company called Dauntless Software that offers test prep software for only $35. You can download it from www.checkride.com. It's called GroundSchool and once you pay for it, they send you an unlock code. I took all my tests using test prep software. I got a 98%, 96%, 92%, and I just took my ATP written last month using it and got an 89%.
Also many Gleim test prep books offer a CD ROM that comes with it for test prep.