I added a link to my original post, but you should definitely feel free to look through more choices. Lite-on, LG, Plextor are other companies making good drives these days.
As for installation, that isn't too hard. Since your computer probably isn't one of the latest, you'll need one with a regular IDE connection, not one of the new SATA connections. The only other thing to look out for is to make sure the jumper on the back of the drive is set correctly. You'll probably want to set it up as the Master on the Secondary IDE channel.
How many optical drives do you have now? If you only have the one, I'll bet it is set up as master on the secondary channel right now. Look at the cable that connects it. It should have a lot of little wires (80 of them) all in one big flat cable. If it only has 40, then you may want to change this older style cable for a newer IDE cable that has 80.
So the process would be like this. Unplug the IDE cable and power cable from the original drive and physically remove it from the computer. Put in the new one (making sure that the little jumper on the back is set to Master). Plug in the IDE cable using the end connector, not the middle one. Plug in the power cable. Restart Windows and let it detect the new hardware.
That would be basic instructions. Let us know if you have any problems.