Do not depend on memorization.Really focus on the application and evaluation pieces rather than just memory recall. We use mind maps a lot in my med-surg class. We include the patho/etiology, diagnostic tests, labs, complications, teaching, interventions & evaluation on the mind maps. The mind maps really provide a visual of what's important with each health alteration. When studying it helps to think it through. What am I expecting to see? What am I going to do first? How will I tell if the patient is getting better? What meds do I expect to be administered? What is contraindicated? etc..
I have found the Med-Surg Nursing Made Incredibly Easy book to be quite helpful, especially for a starting point. I use a couple different NCLEX apps for my iphone too. These let you pick which systems/categories you would like to study, and give question by question rationale. I really like the Mosby's Med-Surg one. All of my instructors STRONGLY recommend us practicing NCLEX questions daily.
Good Luck in your med-surg class!! My med-surg classes are always my fav!