Indeed. Make sure you install to (something like) C:\Games\Oblivion, or similar, and yes,
do use a mod manager. Really. It will save you a lot of pain and angst, again and again. Forever more!
Preferably? Get the hang of BAIN packaging, installation and uninstallation. Second best - by a hell of a long way - OBMM, or OBMM Extended perhaps.
Also, make sure you use the latest BOSS. And all the latest updates. For everything.