The Revalidas in FEU are a series of exams that test your basics... ie anatomy, physio, pharma, etc. Each are bascially long shifting exams composed of 100 multiple choice questions that can be on anything under the sun.
near the beginning of your 4th year, you will get a list of dates that tell you when the revalida exams are. I would then spend the month prior to each exam reading a review book slowly. I used the opportunity as my first read toward gearing myself for the USMLE. That is how I studied, and I passed every single one my 4 th year on the first try. other clerks would cram the week before using old exams and samplexes. But my mode of thinking was this. They are usually testing concepts that are essential to master and understand before you graduate. So use the opportunity as such. Read the review books to review and solidify your knowledge. If you truly know the material you will pass the exams.
The revalidas were usually pretty fair and tested important topics. They were less picky than your typical shifting or midterm exams.
Books to use... the highest rated review book in first aid for the USMLE for the specific topic. I.E. BRS for physio... Lippincott for pharma, etc.