I'm not sure I totally get what you're asking for...
Alot of the things you need are actions from a trigger. Like to be invincible, make the unit invulnerable. Or say you want a time-stop ability, you use the Pause action. For half health do Unit> Set Health to (.5 x (Life of (Triggering Unit))) or something.
I'm not sure what you mean by spell category or options.
Now, how do I make spells? First I need a clear example of what the spell has to do, my latest spell was an escape spell. My friend and I discussed and decided that the spell would be based on blink (the escape part), then all units in a range around where the unit WAS would be cycloned. On top of that, all units that were cycloned would take damage. Once we got down those basics of what I was able to do with the editor and what we wanted done, I was able to go in and mess around.
Mind you, that spell took me 2 hours maybe to get perfected. I must of have made 4 copies of it before I got one that worked.
What you need to understand is that 9 times out of 10 the spell you click is not the actual spell that is performed on a map. It is a dummy unit that is created with the actual spell in its arsenal, then the created unit is told to cast, then after it casts, it is destroyed. That's how most spells are made. That and alot of special effects.
As far as tutorials go? I have no idea. I didn't use tutorials, I opened unprotected maps, took a look, then recreated to the best of my ability. That and alot of mess ups and retries put me where I am now, which is probally just above the amateur level.
The best thing you can do, is try to make an ability using each of the events, conditions, and actions. Make sure each works, and then you have a clear example of what everything does. Or how it works. That's the best way to do things.