Most cheat keys are controlled by your mouse pointer. For example, to use "Ctrl-Q", put your mouse pointer over the character whom you want to join your party, then press the Ctrl key on your keyboard, hold it down, and press the Q key on your keyboard. The character you were pointing at will become a member of your party instantly. This is useful for bypassing dialogue and recruiting creatures who don't belong in your party. With Ctrl-Q, you can make ANY character or creature become a member of your party, including Jon Irenicus, beggars, rats, trolls, genies, etc., etc. Most creatures weren't intended to be party members, so don't expect them to "look right" when you examine their character records or their inventories and so forth. Jon Irenicus is "Chaotic Good" (yeah, right), chickens are 1st Level Mages, and Drizzt wields his scimitar with his teeth (it's on his head). Obviously, you can have a lot of fun with it (I know I did), but don't believe everything you see.
Other cheat keys include Ctrl-Y, which does thousands of points of damage and instantly kills most creatures your mouse cursor is on (it might take a couple of tries to kill certain monsters, such as trolls which need to be hit with fire or acid damage after they are "killed"), Ctrl-J, which lets selected characters "jump" wherever your mouse is pointing, Ctrl-R, which fully heals and "restores" the character you're pointing at with your mouse (it removes all effects), and Ctrl-T, which advances the game clock by one hour (which can make spell effects expire). We're talking about some serious cheating here, you know.
To recap, point your mouse at the appropriate place or character, hold down the Ctrl key on your keyboard, and then press Q, Y, J, Y, T, or whichever code you want to use. Holding down the Ctrl key and pressing the Space bar brings up the CLUAConsole command line, so you can think of Ctrl-Space as a cheat key in its own right.
I hope this helps!