Honestly, all I did was print out a copy of the kana charts and traced over them. I then would hide a few of the letters at a time and see if I could remember how to write them. I did this while I was in class.. A boring class, but eventually I remembered them all. Then, from there you just have to start using them and reading them. But this was pre-iphone. Now, there are a bunch of cool apps for learning kana. Just type in Kana!