I'm travelling at the moment and won't have a chance to write up a standalone answer, but you may find that this older answer of mine covers some of the ground you're interested in, with some background and discussion of why it has often been seen as important by various people. The FAQ section on the Spanish Civil War also contains quite a few older answers on the Spanish Revolution and its key participants - you're of course welcome to ask more specific follow ups if you find there's something not covered that you want to know.