You can get your feet wet with courses at Lynda.com. A lot of it is software training, but there are some basic courses about typography, color theory, and other important building blocks. I think you can get a free trial for 14 days or so to try it out. Good luck!
I also recommend checking out Skillshare. There are several courses there that are work at your own pace and you can post the work you're doing for critique from other classmates and the instructors. It's also a fairly cheap subscription model.
I usually use Google and YouTube to learn basic of any program. You can try on Lynda too. But it is also true that for advance level learning paid courses are better than free videos. For paid courses you can try here http://www.smallbusinesswebdesigns.net.au/about.html