I used to take distance learning classes because I couldn't go to campus due to health reasons. I took everything from biology (with a lab!) to algebra to public speaking online

Other classes I took online were various English classes, economics, history classes, microcomp applications, various psychology classes, humanities, career planning, and information literacy.
I liked distance learning classes and I did well in them, but I like on campus classes better. One thing about online classes is that you will get used to doing a lot of busy work (like weekly message board posts and writing assignments). After taking distance courses, most on campus ones seemed like a breeze to me. Besides not having to do as much busy work, having a teacher to explain things is always a plus in on campus classes, too. When I took my second biology class, it was on campus and it was so much easier than the first one because having a teacher explain things was better than only having the book (which often will not explain things in simple language like a teacher will).
But sometimes you get video lectures for online classes so that takes care of that problem. Plus, you can rewind a video, unlike teachers
For public speaking online, I had to videotape myself doing a speech in front of a certain number of people (I had to make sure to show them all in the tape before starting my speech). That was uh.. interesting. I'm sure for public speaking I got a better grade then I would have if I had taken it on campus. However, I didn't
really get to practice doing speeches in front of a
lot of people so that's sort of a disadvantage.
Math classes online are not cool. There are some perks to having neat software to do your homework with, though. You can do the problem wrong and then the software will help you figure out what's wrong. You can do the problem over and over again until you get it correct, so anybody willing to perservere will do well on the homework. But without a teacher to explain it, math is hard in online classes. I ended up withdrawing from one of my math classes and taking a hybrid course instead (went to lecture AND did homework online). I liked that format better because I got the best of both worlds in that situation (the software and a teacher).
But all of that aside, I did not find it hard to motivate myself to do the work. I knew that because I had a lot of work, I had many opportunities to get a good grade (as opposed to only 3-4 opportunities in on campus classes, where you just have a few exams and maybe a paper and that's it). The other nice thing was that I could do the work whenever I felt best. That isn't an option for on campus classes. I saved money on gas not having to drive to school, too!
If you are taking online classes just invest in a big calendar and a planner, write all your homework due dates down, and work on a little bit each day. As long as you get the work done and turned in on time you should be fine

And you will come out of the experience being more self disciplined than most traditional students are.