We bought a used Doughboy pool on eBay about 5 years ago ($1 - yep one dollar!!) and installed it ourselves. I *think* the new liner came with instructions, or we picked up a pool installation guide from a local pool shop. Whichever it was, the process we followed is pretty much described word-for-word here:

http://www.arthurspools.com/liner/step1.htm

We were a bit hasty and ended up with some wrinkles in the bottom, but that didn't bother us too much. We've had three holes in 5 years - one above the water line from not adjusting the liner properly during the initial fill, one where the floor stretched down where the ground collapsed into a crawdad hole, and lastly when a blade of grass grew up through the liner...