NCEES, the national administrator of FE and PE testing and scoring, provides practice tests that simulate the FE and PE exams. They should be one of your main sources for study material, as they provide a good barometer for the difficulty, length, and scope of your future.
Note that the sample PE test within each discipline have AM and PM sections, just like in the real test. All AM portions of the tests within a discipline are identical, so it is the PM Section that distinguish each test from each other.
Pricing Note: NCEES sells all of these tests for $39.99 not including shipping or tax. Depending on your location, this may be cheaper for you instead of ordering on Amazon.com