Computer Hardware...
So far, you've discovered several great places to purchase computer components from in my recommended parts, and the criteria that you should use while selecting the parts, and if the respective part is even pertinent to you. There are still 2 important parts to a computer left however.
Printer
Printers can be pretty complex, with many options to consider, from how fast you want it printed to ink costs to photo printing. Some printing manufacturers include Epson, HP and Canon, among others.
I generally recommend HP printers, as across the board, the entire line of HP printers tend to use the same type of black ink, and vary relatively little within colors (more supply=lower prices). A good idea when shopping for a printer is to not look solely at the bells 'n whistles on the machine itself, but to browse some more and see how much the ink ends up costing you (as this is the big money stream for the manufacturers; they take their strategy from King Gillette).
Printers are actually relatviely cheap. Printers normally include a full set of ink cartridges with your purchase (the cartridges probably would retail from $40-$60 alone), so you are essentially not paying much more for an entire new printer. You could easily rationalize getting a new printer every two or so years based on this.
When looking for a printer, I would suggest mostly ignoring any special 'photo' printers. You generally will get better quality and a lower cost per picture by using the digital print stands found at nearly every Walmart, Walgreens, or other drug store around. I have seen several different articles where the price difference is roughly $.10/picture between doing it yourself and at the store.
The printer I currently have is the Epson C84, which prints fast and produces
amazing photo prints as well. This concise
review compares the C84 to several other makes available.
Another good thing to look for when printer shopping is to see how they divide up the ink cartridges. The printer should at least have 2 cartridges (one for black & white and one for color), but mine has four (black, cyan, magenta and yellow), which will lead to less ink consumption and thus prolonged ink life (and savings) for you.
Keyboard & Mouse
The Logitech Cordless MX Duo is probably the most useful Christmas present I've gotten in awhile. The mouse feels 100% natural in my hands and both the keyboard and mouse have a surprisingly long range. The handy thing about the cordless mouse is that it has rechargeable batteries, preventing you from having to worry about batteries for quite some time. There are also several other options I recommend for keyboards as well.
Next - Digital Cameras - Take a Bunch of Pictures »
Tip: An area I feel that most people do not consider when computer shopping is your keyboard and mouse setup. The additional functionality and utility that a cordless mouse/keyboard combo has proved invaluable and a lot more comfortable than being tethered to cords.

