What are good ways to learn more about opposing schools of thought in sme detail?

I'm familar with only the very basics of Keynsian theory and Marxism. Really, AD/AS, and LTV. Their founders, however, each filled tomes with their ideas. And it's worth learning more of their arguments--after all, you can't criticize them effectively without a solid understanding of them. To this end, what's a good way of learning more of either? Possible difficulty: I'm not an economist by trade or training; I've only had Intro to Macro and Micro. So I'm unfortunately unable to follow high-level arguments. Is there anything out there you know of that would fit this need for me? I'm doubtful myself, but figured it couldn't hurt to ask. I did see the History of Economic Thought links in the sidebar, but it doesn't look at if those are likely to go into sufficient depth, though they may be a good starting place.

link: http://ift.tt/1oO9pvL