The key takeaway should start with Buyer Beware. I have found YouTube helpful in learning how to do specific tasks with home repair, car repair, etc. They are wonderful and much better than any tech manual I have ever used in the past. On the other spectrum, I am trying a course in biology from a free on-line course from Carnegie Mellon University. Self paced with excellent expiation of basic principles and short tests to make sure you understand the concepts. In the middle are these get rich quick schemes that are no different than the ads we saw in magazines that now just happen to be on line. Students should first understand their objective before giving away your hard earned cash.