Studying Korean with my sis

I have gotten myself into a bit of a tight situation. I promised my sister that I would study Korean with her, but it's proving to be a lot more difficult than I thought. I still want to keep going, but I know it's going to be really hard.

I learned about present tense endings, and there is already a lot of rules. Luckily, the summary always helps me gather my thoughts. There are only 3 verb endings for present tense, but there are a lot of little rules associated with the vowel and consonant endings (which is driving me nuts). I am trying to read over the rules on the 90 day korean website, but it's not really sticking. I think I'm going to have to study this for a week until I feel completely comfortable with it. It's one of those things that you have to get used to, or you'll always be getting it wrong.

And for those who are curious about this language, the 3 verb endings for present tense are:

-아요

-어요

-예요 (해요)