I have learned all my punctuation knowledge from reading books and noticing how it's done.
I rarely go to formal grammar lessons for anything I use in everyday life. It's mostly just noticing, acknowledging, and applying.
Although I do want the grammar book I bought for $80 and loaned to my brother's friend two years ago back. D<
But either way, my best advice is to read books and pay attention to what's in those books. But not Twilight, though. That book would make an English teacher cry.