First thing's first. Start learning about triggers, about how they act and how to manipulate them. Don't start with spells. Start with other kind of triggers, learn how to work with events/conditions/actions and of course, start to get the hang of them. Its quite a serious work, so you'll need lots of time for it. Secondly, play with the object editor and learn how to manipulate spells. But don't upload any spells made only in the object editor on this site. Most noobs can do them and so, they do not fit the standards of the section.
After you have achieved these two points, start combining them. Make a spell, and start working it with triggers. I can't tell you much about this. Experiment! And have fun!
~Daelin