The first thing you should pay attention to is motivation. Set a goal and head towards it, despite all the difficulties. And it doesn't matter what is your goal: going to College for a medical specialty or simply an extension of the horizon of knowledge. Motivation will help you if you are tired and just want to quit.
How fast would you have liked to learn the subject, know that trying to learn a large amount of material in a short time still not worth it. Otherwise you will constantly confuse, forget formulas and so on. Therefore, it is better to pay attention to the systematization of knowledge: each lesson will devote one section, and after studying a topic start a recurrence and strengthen the material covered. By the way, try not so much "cramming", but to understand. What you understand, not just memorize by heart, you will remain in your memory much longer.
Attach the studied theoretical material, solving the problem. They also help to better memorize and learn to analyze covered. Thus, you will be able to draw conclusions and sistematizarea what is already learned. The decision task allows better and faster understanding of this new material.
Not to forget that you've mastered a few months or even weeks ago, make something of type of tests and examinations. Repeat the material from time to time. By the way, great help with self-preparation can become a theatre company and self-help books, which abound both in conventional stores and on the Internet (you can download free textbooks, not necessarily to buy).
To test your strength, test for knowledge, trying to explain to someone what they have learned. Try not to hurry, tell in detail. Thanks to this method it is possible not only to fix the material, but also to detect "gaps" in knowledge.