Tandy, Weaver Leather, Springfield Leather, Don Gonzales, JH Leather, and Joe Meling are all great places to start on youtube. There are others, of course. Once you chew through that material, and you're looking for more advanced/greater detail information then I'd highly suggest a subscription to Leather Crafter's Journal. If you prefer video-based learning instead of live workshops, then I'd also highly recommend Elk Track Studios. They do have 50% sales frequantly, so you can always wait to buy more videos.
But if you are fine learning from books, you can just skip to the source material for most leather crafts: Al Stohlman books. Tandy still prints a lot of them, just be sure to check out the big format books that look like they're from the 1950's, especially if you want to do leather carving.
Some advice you didn't ask for: Always buy the best tool you can afford. Tools do not magically give you experience(in fact, buying different tools to do the same thing will just slow you down). The more you do something using the same tools, the better you will get at doing it.
