Step-by-step guide to hotkeys in Skyrim:
1. Add whatever you want to hotkey to the favorites menu
2. Open the favorites menu
3. Hover over the thing you want to hotkey
4. Press one of the numbers above qwerty. Works for 1-8
Voila. Hotkeyed.
Protip for spells --- double-tap a hotkey to put that spell in both hands.
I could probably write a "Doctor grade in usability" based on Skyrims user interface. Not because its bad, it isnt. Very cool interface, thin and clean, but so damn hard to use.
Look, let me just point out one single thing:
When you press ESC and go to Save/Load, you are able to use Mouse to brows and select different save points. When you go to Inventory->Weapons subcategory, you cant do the same thing. My point being that Skyrim interface is unintuitive and difficult to use. You should be able to complete any task inside of inventory with either Mouse or Keyboard. I cant and if people think I am too dumb for this game, than perhaps I am.
Here is another example of how one can struggle against Skyrims interface. Did I mention that Favourites menu is a brilliant idea? It is, I mean it. I love it, but you could improve on it.
I wish to equip Fireball spell into my right hand and Lightning Bold in my left. Prior to this I used to dual cast lightning bolt and right now I hold two-handed weapon. So I go to Favourites and use my Left mouse button to click on fireball. Nothing happens. I right click on it and an arrow with letter L appear in it. Did I mention the overuse of white coloured pointing arrows in Skyrims interface?
Now I got Fireball in my left hand and Lightning Bolt in my right hand. Insanity does not stop here.
I try to cast one spell after another, holding down Left Mouse button to charge Fireball (which is firmly put in my left hand on the screen)................................ Charges lightning bolt in my right hand on the screen.
That is why my cat-like-woman goes Sith Lord style casting Spark from both hands.
In order for me to hold Fireball in my right hand, I first have to short-cut it to a number, than press the short-cut, then go into Favourites and select Lightning spell. Now I have Fireball in my right hand and Lightning Bolt in my left. But mouse buttons are still [censored] up. My room mate plays it on Xbox 360 and he has no problem with triggers on xbox controller... Some people report using Directional arrows to solve their, left hand, right hand problem. I just ask them "What the hell do you have a mouse for then?"
P.S. Taken out of context from http://www.gamesas.com/index.php?/topic/1267247-skyrim-from-user-point-of-view/