NewEgg.com ZipZoomFly.com are the best online computer sites. I order things from them at least once a week.

For keyboards, Logitech is good and cheap, as with some microsoft. You can get a wireless keyboard/mouse from Logitech for under $80. Monitors, for CRT, the brand really shouldn't matter, but ViewSonic is good, unless you're going for LCD, I suggest maybe Acer or Viewsonic for CRT's. In 17", that should be well under $150.

Do you already have a router? If not, that's what you'll need... jsut read about your dad's occupation, scratch that, he'll take care of everything in that end.