Reddit mentions of What is this thing called Knowledge?

Here are a bunch of resources to get you going:

Philosophy for Beginners is a free introductory lecture series from Oxford University.

The Problems of Philosophy by Bertrand Russel.

Check out podcasts. Philosophy bites is a good one for beginners. Here's one on epistemology: Jennifer Nagel on Intuitions about Knowledge

What is This Thing Called Knowledge? is a good introduction to episteology.

Some classic that are accessable for a beginner:

• Meno by Plato and listen to We Don’t Need No Education: Plato’s Meno
  
• Meditations on First Philosophy by Descartes and listen to Cogito Ergo Sum
  
• An Enquiry Concerning Human Understanding by Hume and listen to David Hume
  
  And here's a free lecture course on epistemology.

Metaphysics:

Conee and Sider's Riddles of Existence is a good place to start, I think.

You might also be interested in epistemology, given your enjoyment of the Matrix. Some epistemologists argue that we cannot know that we aren't in matrix-type scenarios.

Check out Pritchard's What is this Thing Called Knowledge? for a very accessible intro.