I always recommend an intro physical geology book to start your preparation for the ASBOG geology test. In recent days, the physical geology books got way nicer and colorful and they cover tons of great materials. Just pick up any recent physical geology book and you are good to go.
Initially I thought about putting together all physical geology questions under one quiz. Well, after preparing the question set for the fluvial part only I have got more than 65 questions already. So, I decided to present the sample questions on fluvial geomorphology (river action) separately than other parts.
In fluvial geomorphology there are few important things that you need to know such as the various stages of river formation, river morphology, types of valleys, types of rivers (braided, meandering), drainage types (trellis, rectangular, annular etc) and some bedforms related to erosional and depositional action by flowing water (cut bank, bars, ox bow lake, delta etc).
I will try to update this post with short study guide as soon as I can. In the mean time, enjoy the test.
Also consider taking a look at my other ASBOG tests and lessons: