[insidious]

That said, I advise you to do some research beforehand, so you can avoid the common pitfalls in freelance work. Underpaid work is a particular issue - some major brokers of freelance work are practically slave labour. I used to do freelance writing through services like Textbroker, and you'd get paid less than two cents a word. At the time, I hardly knew better, but that was definitely much less than what some of my work was worth. (I think that's more common in writing than programming, though. Correct me if I'm wrong.)

That said, even my work for Textbroker eventually paid off. I got a lot of experience and a solid portfolio worth of work done that helped me land better jobs later on. Still, just be careful not to get ripped off if you can. People can and do live full-time off freelance work, so it's not like there aren't well-paying jobs out there. Just need to do your research, and know what you're willing to accept. (And what you're not, by extension.)

Blacksmith is right, definitely do the research.

Another thing to be weary of doing freelance work is finding the motivation to do it. Since you are the boss, it can be difficult at times to just do. Without a 9-5 boss hovering over your shoulder and making your palms sweat, it's difficult for many trying to break into the freelance world.

IF I were to recommend you one thing, it would be to make a psuedo-schedule for the week, where you take into account absolutely all of your responsibilities for that week. Try to estimate the time it will take you to do each task, and note it down.
Make a calendar of your 'fixed responsibilities' which MUST be done at so-and-so time (IE: classes, underwater basket-weaving practice, etc) . Then, for the tasks and the time allotments you have left over, put them into a todo list.

At some time every day (preferably in the morning) take the variable tasks that you need to accomplish and allot time to do them in that day. Obviously, there is flexibility in this.

But make absolutely sure you try your hardest to do that task at the time you alloted. DO NOT procrastinate. Procrastination may be the bane of your existance depending on your personality (I know it's the bane of my existance).

This may not work for everyone, but part of this is discovering what works for you. Try out different productivity strategies, build, test, etc. Soon enough, you will find what works for you and be making the big $