There is a gui now to rebind keys, but in case you want to mess with stuff not listed in the in game options:
Find your League of Legends config defaults folder (probably c:\Riot Games\League of Legends\game\data\cfg\defaults) **DO NOT EDIT ANY OF THE FILES IN THIS FOLDER** If you edit any of these you might break something and have to reinstall.
Find Input.ini and copy it. Go back up 1 level so that you are in the CFG folder and paste it here.
Open it (using notepad or wordpad if it asks you to pick a program)
At the top you will see a bunch of
;"[Esc]", //DIK_ESCAPE 0x01 ;"", //DIK_1 0x02 ;"", //DIK_2 0x03 ;"", //DIK_3 0x04
[DisableKeys] disableCapsLock = 0 disableWinKey=0 disablNumLock = 0 disableLinkedModifers = 0 [MouseSettings] PointerSpeed = 2 RollerButtonSpeed = 1
[GameEvents] evtCastSpell4 = [r] evtCastSpell3 = [e] evtCastSpell2 = [w] evtCastSpell1 = [q] evtCastAvatarSpell1 = [a] evtCastAvatarSpell2 = [s]
The items are under evtUseItem7, which is the bluepill, followed by the inventory in reverse order.
The hold command for your character is listed as evtPlayerHoldPosition = [h].
The momentary way to center the camera on your champion is evtCameraSnap = [Space].
When you are done, save and restart LoL and enjoy =D.