I just did a search for a katakana chart and came up with plenty of links, finding a good chart should be no problem... http://hem.passagen.se/bomark/japanska/katakana.html looks pretty good to me. There's also a few rules you should know if you're going to converting English into katakana, like a small tsu character doubles the next consonant sound, and use a dash to double the preceding vowel sound. (Maybe you already know this, I'm just trying to be helpful with what little knowledge I actually have ) Can't think of any other ones right now.