I donwloaded rens beauty pack and I was wondering what the ~ command to allow me to change my hair. I remember on Morrowind it was enableracemenu but that doesnt seem to work on Oblivion

Showracemenu

However, do NOT click accept. It will reset your stats. After you change your hair, make a save. Then load that save.

Its showracemenu select your hair you want and click save dont hit done itll screw up your attributes. Then reload that save and you got your new hair.

Thanks the menu pops up but none of Ren's hair is there. I made a new character and all of the hair was there for him and i even used the showracemenu in the jail cell after i made a character and it was still there. Its just not working for my older character

Should work if your older character is a vanilla race - if a custom race you might have to set up Ren's hair for it.

My character has one of Rens hair when I first started the game but now that I'm out of the sewer I want to change it to a different hair style and none of Ren's hair shows up and the hair that I have chosen the name for it is blank and if I go over to a different hair and then try and go back it isnt there

Maybe the problem with the old character is a load order discrepancy with that save file. Have you investigated that possibility? That sounds like a bug, anyway.

Please, post your load order - http://tesivpositive.animolious.com/?page=know_how_to#PostYourLoadOrder

Oblivion.esm
ShieldOnBack.esm
All normal clothes buyable.esp
_Ren_BeautyPack_onlyhairs.esp
Knights.esp
DLCShiveringIsles.esp
DLCBattlehornCastle.esp
Breton Elf Ears.esp
mageitems.esp
Chapel Shop.esp
DLCVileLair.esp
DLCThievesDen.esp
DLCOrrery.esp
DLCHorseArmor.esp
DLCMehrunesRazor.esp
DLCFrostcrag.esp

Is your character a Breton? That mod, if it does what I assume it does, conflicts with Ren's mod. A Bashed Patch would take care of that conflict for you.

Official and Unofficial Patches - http://tesivpositive.animolious.com/?page=official_and_unofficial_patches <-- Grab the UOP.
Load Ordering - http://tesivpositive.animolious.com/?page=load_order <-- FYI
Wrye Bash - http://tesivpositive.animolious.com/?page=wrye_bash <-- Installing it is not as complicated as some make it sound.

After sorting your LO, adding the UOP and taking care of that one conflict, your setup should be a little more stable overall.

Import-Edit-Export Character Face - http://tesivpositive.animolious.com/?page=tutorial_import-edit-export_character_face <-- This tutorial explains how to take advantage of Bash and TESCS in order to have a little more freedom with character modification.

I am creating screenshot-aided tutorials today, so let me know if you want to see a screenshot added somewhere as an aid.

Alright thanks! Im downloading the patch as I type this and Wyre bash just finished

All right, cool. Be warned, if you are running Win7 or Vista, in order to be sure Bash installs correctly you may want to disable the UAC temporarily. That is not a necessary action, but if after installing the Wyre Python 3a package and then Bash, Bash does not work, you may want to reinstall everything with the UAC out of the picture. When you launch Bash the first time, a little window will popup that looks like an error message from the ComTypes component, and you can just ignore that.