I'm new to the game and having a ball with it! I'm very close to completing it, and I want to play all of the DLC's. But I bought them and they all are in launchers, does that mean I can only play that dlc in that launcher? If so is there a mod where I can play the DLC WITH the regular game?

No you don't need to use any special launcher. Just make sure they're enabled and they will appear in the main game. In fact you should get notifications for almost all of them right away in the tutorial dungeon, unless you're using some sort of delay mod. If you haven't already received any messages about them, then they probably aren't turned on yet.

The launchers install the DLC into your existing game. Do not delete the launchers after you have installed the DLC in your game, place them on a remote hard drive, or a disc. You may need to reinstall them again at some point. You will want to use the Unofficial Oblivion Patches for the DLC you install into Oblivion, The Supplemental Patches by Arthmoor fix bugs the Unnofficial Oblivion Mod Patches did not fix.

They install them to your Data folder, but you still need to turn them on after that. If you first stick your disc in the drive there'll be an menu option on the screen that pops up. I forget what it's called, but you need to go in there turn them on. If you you're on a PC though, you're better off using OBMM (Oblivion Mod Manager) and do it through there.

Ohhh thanks everyone! I totally thought they were like seperate launchers for the game, not installers haha. Thanks for all the help guys