[quote name='pinebarrens']I bought a new taillight off of ebay for my 2000 civic. Anyone know a good "how to" website that will give me some guidance on how to install it?[/QUOTE]
Usually the owner's manual has a section that guides you through simple maintenance tasks like replacing tail lights. There's probably a bolt or two inside the trunk behind where the light is. You'll likely need a metric socket wrench to remove them. The compartment should pop right open, giving you access to the tail light.
Before doing this, I strongly recommend putting a bandana around your forehead, cracking a beer and setting it on a paper towel on the roof of your car, and blasting Whitesnake from a boom box. Tends to make the process go even easier if you've got an absurdly large tool kit next to you on the ground.
Good luck out there!