I don't know... I memorized the kana first, but I've been working on my kanji as much as possible. And, while I am taking things very slow and could probably be much better in spoken Japanese if I only dealt with kana and romaji for the time being, I think I have a better understanding of what I do know because of my kanji. Everyone learns differently, though. If you want to try kanji as well right away, though, try the book, Essential Kanji for your kanji studies. I tried quite a few other kanji books, and this is the one I liked the best. For grammar and stuff I use the Japanese for Busy People I (Kana Version).
Ewok's right though--even if you do start with kanji from almost the beginning, take two weeks to get through the kana first. (That's how long it took me for both syllabaries, I think it's about an average time.)