The only review materials I've used was the Kaplan 2009-2010 OAT Test book. The difficulty was slightly harder than the real OAT. Practice working fast! Each question is designed with a shortcut to make it possible to spend an average of 50 seconds per question. My opinion is that, given 2 hours of testing time, everyone with a highschool diploma can get a 400 on this section.
Here was an awkward question on my exam: Calculate the volume of a dodecahedron (12-sided polygon with faces of an equilateral pentagon) given the length of a side is L meters.
Sounds difficult right? Even approximating its volume to a sphere is difficult. The correct answer was looking at the answers, noting that only one chocie had the correct units of cubic length. There were a handful of weird questions like this, but a majority of them were basic alegbra (solve for X) or involved fractions (rank the following in increasing value: 5/7, 36/43, 504/680) or trig.
I recommend knowing the values of square root 2, 3, and 5.