I post my studying tips at least once a month in a long and drawn out, multi-paragraph, rant... and normally, I'd get agitated and ignore the topic. But for you? For you, I will give you my usual speech on studying, studying habits, and test taking tips that have helped me maintain my 4.0 GPA in university.
My best tip to you is to pay attention in class. Doodling, sleeping, or chatting with the person next to you is a total waste of your time. You will not learn by osmosis.
What to study from? Well, that really depends on how your mind processes information and recalls memory. ("Are you left brained or right brained?") For some people, reading out of books over and over again will allow them to memorize things. I'm more of an auditory learner... So I typically prefer courses that are nearly entirely long lectures as I recall sounds much better than images. I also find that I learn best by learning key words/phrases/ideas and expressing them mentally or sometimes verbally to a rhythm. I'll repeat the string of seemingly random facts, ideas, or concepts to some beat that I create and am able to recite it as if it were a musical lyric. What works for you is going to depend highly on how you learn the best, though!
Test taking tips? I know how over done this is... and I was never a big believer in it until I got to uni. Your best test taking tip is going to be get a good night's sleep! 6-8 hours is the range you want to be in. DO NOT sleep for 9 or 10 hours. DO NOT sleep for under 5 hours. Your memory will be fucked if you do. You can look up sleep studies and the correlation to aging, disease, and memory function via google.

So now you've gotten a great nights sleep, eat a healthy breakfast! I like to ensure I get carbohydrates along with protein and sugar, but if you are unable to eat something like sausage, bacon, or eggs, just some toast and a glass of orange juice will do you wonders! (If you can stomach it, I'd actually recommend a peanut butter and jelly sandwich with milk!) The goal here is to maximize your energy levels and to get your brain functioning at a high level early in the morning! You need plenty of fuel to really launch on your exam.
Another of my major recommendations is to study the day(s) before, but don't cram. You don't want to over-saturate your brain. Give yourself plenty of breaks, go do things you enjoy in between... It can be good to study in short bursts because when you start to become over-saturated in the material, you are no longer really retaining it. I would suggest making notations (even if they are only mental) of the topics of the subject that you need the most work on as you do a quick glance over review. Focus on those topics for your studying, and don't waste your precious time on the material you feel you adequately grasp.
One of my other key points is to do a brief glance over some of the material you needed to work on the most over breakfast and for 5-15 minutes prior to heading into your exam. This will give you a brief assessment of the things you needed help on and also keep those things you needed the most help on in both your long and short term memory, allowing you the best results on your exam!
Finally, take a deep breath before your exam and don't stress out about it. Nervous energy is healthy, but if you let your fear or stress eat at you while you take the test, you will perform much poorer than otherwise.
So to summarize; Pay attention in class, find what works best for you to study, don't cram for exams, get a good nights sleep, eat a good breakfast, glance over your material in the morning, and don't stress out! Prepare for easy A's.
If you have any further questions, you can search my previous posts or feel free to shoot me a pm.
P.s. if you are interested in performance enhancing drugs, I'd suggest aniracetam. I've tried three of the four most common *racetam's and found aniracetam to give me legitimate boosts with minimal side effects. (piracetam didn't do much for me at all, and pramiracetam fucks my sinuses up so badly that I bleed and get sick every time...) Take the aniracetam about 1.5 hours prior to the start of your exam and on a good meal or with a fish oil pill for best absorption.

(You can also pm me further for more information on nootropics.)