As a college Sophomore you probably have figured that out by now. 
I have a photographic type memory. I can see the words on the page and sort of re-read them in my mind. But when I take notes they are all over the page. Little jots of data and I will generaly circle them. Draw a star beside them, put exclamation points. To look at my notes you’d think all I was doing was just doodling. But when I go back to them, it’s more like one big picture.
I learn best by hands-on-experience. That coupled with a manual, or some other form of instruction EXCEPT for the lecture. I’m a good listener when it comes to human needs, but not when it comes to a lecture. LOL
My advice to you. Is to take one subject at a time.
for the math I think the best thing to do is to give yourself practice problems that will cover each of the areas that you have learned. Make sure you have a way to know that your answers or your methods are done correctly. But math is like music - you need to practice.
Government and Bio are a little different.
I think an outline is a great learning tool. Write the words. Write with pen or pencil -whichever you prefer. Writing is better than using your computer to make notes. Writing the words is different than using a yellow highlighter. It forces you to determine what is really important. Yellow highlighters can end up making an entire page of notes YELLOW. :-) But when you put pen to paper your brain retains more. IMO.
For Bio espeically I’d go through each Chapter. Look at section headings. Pick out one or two statements that summarize. Read and DO the Study Guides if they are provided. Even if you’ve been taking notes all semester long I’d have whatever text you used handy. Also your labs. I hope your instructor has given you some clue as to what may be covered in the exam. Pay attention to that. If not, you should figure that the lab work is definitely going to be part of the exam.
Even if you think it helps. No TV, no radio, no iPod - IOW no distractions. Study for 30 to 40 minutes and then give yourself a stretch. Take a quick walk around the rooms, run things through in your head, but move around a bit. Give yourself a definite break after three or four hours of study. Get out for a meal or something. Don’t do things that are hugely distracting, like a movie or a novel. Just allow what you’ve learned to be floating around your thoughts and don’t try at this time to take on something new.
Breathe! It’s important. Not too much caffeine. Eat properly and at the right time. Give yourself plenty of time. Cramming should be saved for those very last minute final summaries, not trying to learn the whole semester in one sitting. ;-)
I'm not going to give you any widgets because I don't want you to be distracted by trying to learn "how" to study when what you need to do is STUDY. LOL