I'm a professional geologist with a decade of experience in mining and hydrogeology.  I've taken the materials I used to study for the FG and PG and reorganized them to make studying easier for everyone. The best way to learn is by doing.  Don't waste time and money learning the minutiae of minerals that will never come up on the exam.   All my exams include instant feedback to all my questions so you not only gauge how prepared you are but can learn along the way.