While playing, hit [~] to bring up the console. Then type in "DebugMode 1" without the quotes. You may then use the following codes. (Note that all codes are cAsE sEnSiTiVe.)

irolltwenties - 20 in every statistic.
givespell # - Gives a spell identified by it's id number to the character.
givexp # - Gives the desired amount of XP to your character.
dm_god - Godmode. Unsure if it actually works, but it does not return an error message.
SetINT # - Set Intelligence to given number.
SetCHA # - Set charisma to given number.
SetCON # - Set constitution to given number.
SetDEX # - Set dexterity to given number.
SetSTR # - Set strength to given number.
SetWIS # - Set wisdom to given number.
commands - List Commands.