1.If I didn't understand the book,I went out and purchased another one that I could understand better.There is no such thing as an "easy" book but some books can explain concepts better than others.
2.I went to the professor as often as I could.Some professors will go our of their way to help you (I've been blessed to go to a school where nearly the entire math and science division will stay long hours just to help you).Going to a professor on your own time also lets the professor know that you are concerned with your learning of the material and that could help out quite a bit.And don't feel like your hindering on a professor.Their job is to help you understand the material.
3.Practice Practice Practice.It seems obviously but you won't believe how many people fail to abide by it.When I was in Calculus I,we were studying Related Rate problems and I was completely clueless.Since it was the weekend and I couldn't find my professor anywhere,I tried a problem with different approaches,when I found the correct approach,I went to the next problem and worked on that one.I think in that one night I worked over 40 Related Rates problems and by that time,I basically mastered the concept.
4.Keep a math journal.It seems silly,but I kept a journal with problems,solutions and even a few words describing how I was feeling at the moment.With this journal,I was able to analyize my weak points and my strengths.
5.Anybody that is discouraging you,I would recommend to stay away from them.That discouragment and unneccessary babble will destroy you (and your grade) if you are not careful.
6.As soon as you finish the class,don't immediately throw the book out the window.Keep it as a reference source and when you have freetime,go through and work some problems.This will keep your mind active and you won't forget the material.I had just finished my course in Calculus IV - Linear Algebra.If most of my classmates from that class went back and took a Calc I,Calc II,or even Calc III course,they would probably fail it because they simply allowed themselves to forget.Even to this day,I still work out problems from every level of Calculus I've had and this keeps me fresh on concepts (and it also allows me to help other students).Keeping up with previous concepts is important because math builds up on previous concepts.