Hit the tilde (~) key and type in

 DebugMode 1

(case sensitive). Then hit the [~] key again and press [Tab].

 This should show you a list of the different functions available.

 Hit [Tab] again to scroll down the list.

 m_god    - God Mode
 dm_heal X    - Gives you X health
 dm_givegold X   - Gives the X amount of gold to you
 GetLevel X   - Raises you an additional X amount of levels
 SetCON X   - Sets your Constitution to X
 SetWIS X   - Sets your Wisdom to X
 SetINT X    - Sets your Intelligence to X
 SetSTR X   - Sets your Strength to X
 SetCHA X   - Sets your Charisma to X
 SetDEX X   - Sets your Dexternity to X
 GiveXP X   - Sets your Experience to X
 SetAge X   - Sets your Age to X
 SetAppearance X - X1 <= X <= 290

 ModSpellResistance X - Sets your Spell Resistance to X

 (X = Number)