What you'll need:
Iso-Propyl Alcohol (if you've got it)
Acetone (nail polish remover)
Rotary Tool (Dremel etc)
Plastic or Glass container
Most of this stuff you should have lying around or can borrow from friends/work. The Copper Clad Boards, Alcohol and Liquid Tin is easy to pick up from Maplins or Rapid.
Step 1: PCB Design
If you're designing double sided boards you'll want to have a few holes somewhere that you can use to align both sides. I usually add an extra centimeter around the edge and put a small hole in each corner (this also gives room for a bit of error when etching).
You'll want to flip/mirror the front image so it is the right way around when you transfer it onto the copper. If you've done the back as if you were looking straight through then you don't have to flip that side.
The most important thing in my opinion is to fill in all blank areas black. When you're ironing it onto the copper the black areas will stick to the board, making it easier to iron and harder to rip/crease.
Once your design is complete, do a test print on normal paper and check everything is OK, then when you're ready feed a page of the magazine paper through the laser printer and print it out (I find thin, flimsy magazine paper is the best).