List of Material that can be Recycled in Austin TX and How?

I would like to help the world be a healthy place for my family. Unfortunately I never learned anything about what can be recycled and how. EX: when I recycle envelopes do I need to take off stamps, the plastic front and the sticky back? Anything that would help me learn how to waste less and Recycle more would be great. Please no Rude comments. Thanks