Paper

• Paper (copy paper, newspaper, magazines)
• Cardboard
• Junkmail

Exceptions: Anything with food stains, which contaminate -- so no pizza boxes, Chinese food containers, used paper coffee cups, tissues, etc.

Plastic, Glass, Metal

(Rinse if possible)

• Cans: All aluminum and tin. This means soda cans, soup cans, etc.
• Plastic: All plastic bottles and containers, cups, etc. Caps are fine.
• Glass: All glass containers
  

Exceptions: The heavy plastic that some Chinese food and deli soups come in.

Important note: NO PLASTIC BAGS!
Most supermarkets have bins to collect plastic bags, which should be free of food and paper.