When choosing a paper, there are some terms to look for and be familiar with:
Post Consumer: Post-consumer paper is produced using paper that has already been a product (and probably put out at your curb). It is different from pre-consumer waste, which is the re-introduction of manufacturing scrap into the production process.
Recycled: A new product that has been made from re-processed materials. Recycled products can be made from post-consumer or pre-consumer waste.
Recyclable: A product that can be re-processed where facilities exist.
FSC or SFI-certified: Forest Stewardship Council or Sustainable Forestry Initiative-certified. These schemes identify and verify environmentally responsible papers.
Tree Free: Refers to paper that does not use tree fiber, but other kinds of fiber (i.e. hemp, sugar cane).
PCF: Process Chlorine Free: This most commonly means that the paper was produced without chlorine.
Changing from virgin paper to 100% post-consumer paper makes a huge difference.