Re-learning Oblivion

I am revisiting Oblivion after a very VERY lontg hiatus from the game.
I find there is a lot I have forgotten.

How do I trap souls in the soul gems?? Or can I even do that. I
forget.

Like I said, it's been a very long time.

You have to cast soul trap on your victim before killing them, and the soul
that can be trapped is dependant on the size of the soul gem. Don't you have
to make black soul gems at that altar up the mountains so you can trap human
souls? Azura's Star rings a bell also, and the Umbra sword. But again, its
been a very long time since I played. I've reinstalled with the OOO and
Quaarl mods, but have am still in the sewers. Fallout 3 is taking up all my
time at the minute.