Homebrew PCBs

Assuming you want to use the laser printer (and not an inkjet or other
print/etch technologies), there seem to be two basic techniques.

First, toner transfer.  Easiest way to get started (if you don't mind
spending a little for equipment) is to get Pulsar's starter kit, which
includes a laminator, the water-release paper, sealer foil, some PCBs,
and maybe even the solvent (requires hazmat shipping).

Second is photomask.  You buy pre-sensitized boards, print to a
transparency, and use UV light (or sunlight) to expose the mask.
You'll need some chemicals to develop the mask, and a mini-darkroom.

For both of these, you'll need etching chemicals too.  One choice is
FeCl, which you can buy at your local Radio Shack.  The other is a
H2O2/HCl mix, the parts for which you may be able to buy at a pool
supply shop.