Hardwood floor installation is a skilled job and repairs are difficult; engineered floors are easier, but still require some skill with a saw and are just thin veneers of wood or plastic. We have often said that the greenest flooring around is probably sustainably harvested hardwood but that is not for the do-it-yourselfer, and people often need floating floors when installing over concrete in apartments.
Then there is Puzzlefloor, which takes sustainably harvested hardwoods and makes 5/8" puzzle pieces out of it and finishes it with a 10 layer urethane/ aluminum oxide coating for durability. However what we really like is the process.
They provide "a guide to measuring your room(s) which contains all the info you need, as well as sample sketches and downloadable drawing grids in both metric and imperial measures to help you create a floor plan quickly and easily. Email or fax your sketch to us and we will create a layout to scale using custom software which calculates the exact number of pieces required, including trim allowance."
So you are not just buying lumber in the yard, but part of a system of design, delivery and easy installation.
The Puzzlefloor is manufactured by Briggs Engineered Wood Products, which gets its wood from Nexfor: "Their woodlands operations are fully accredited under the internationally recognized standard, ISO 14001. Fraser is also recognized as being verified to the Sustainable Forest Initiative Program (SFI SM 2001), as established by the American Forest and Paper Association. This program specifies rigorous environmental and conservation practices for forestry, wildlife, water quality protection, biodiversity conservation, and harvesting practices." -Not quite FSC certified but better than clearcut.