Try at wc3campaigns.com for more info. There is a tutorial section... Search there for two topics, both with the thing you are looking for, into the Trigger/JASS forum. Good luck!
Open up a previous map and learn off those. I personnaly learned off of Cube D and Twilight TD. The simpler the map the better, so dont go opening something like NCCD.
Without knowing triggers you cannot begin learning spells with triggers obviously. So I wouldn't try other spells, since some may be made in custom script (JASS) and if you don't know GUI (normal triggers) it will look veeeery spooky.
JASS are triggers in a programming code. This means that you can freely edit it, but unfortunately unlike triggers you have to know the codes. You no longer have boxes with options for actions, conditions and events so you have to write everything by yourself.
I'm decent at making spells through triggers. But I don't know how to import these spells you can download off the page. When I go to import, the files don't show up. I read the FAQ but the FAQ isn't very well written and confusing. Please Help
Copy-paste into your map all the spells related to the original spell, all the dummy units and all the triggers. Oh, and all the buffs. I find this fair enough..
The_HeadSpliter - I never said working with JASS. I just told you that the tutorial forum includes tutorials for both triggers and JASS. Check only the triggers ones.