Re: AR-15 build list
AR15BUILDER.COM has a pretty good basic breakdown of all the items to build an AR, plus you can see your build as you go. Or you can look at an AR exploded schematic to view all the parts of a basic/standard build config.
If you're building upper/lower from scratch, the upper/lower parts kits will have all the springs, pins, and parts to build the gun. It's up to you to decide if your going with A2 style front sight post vs lo-pro gas block, gas system length vs barrel length, flattop vs carry handle, fixed stock vs adjustable stock.
Look at any AR forum pic thread for ideas and get creative to fit your needs. Good luck!