» Sat Sep 17, 2011 9:56 pm
Yes, you will need an application to deal with archives (e.g., 7zip, Rar, Zip, etc.) http://www.7-zip.org/ (<- link) itself is an excellent choice, and is freeware besides. But if you already have something like WinZip, that is okay too.
Oblivion Mod Manager is fine, if you don't want to install very many mods, or much beyond retextures (like QTP3, say).
Just make sure that, whether you use OBMM, BAIN, or both, you apply archive invalidation - but once only. So, either use Wrye Bash OR Oblivion Mod Manager to do Archive Invalidation. You can use either one, or both, to install/configure mods, however.
Feel free to ask more questions, if you need to. The first thing to remember, though, is: read readme files and other documentation thoroughly, and follow instructions to the letter.
You'll be fine, if you do that.
edit: Also, if you are running Windows 7 or Vista? Make sure you install Oblivion somewhere outside of the usual places (maybe try C:\Games\Oblivion or the like). This is very inmportant! Uninstall and reinstall, if need be.