ok, here's what my friend told me. he's already in the biz. he said put together some of your finest work, including a finished manga, and head to some of the conventions with editors walking about and hassle them to look at your stuff. lol. That what he did to get work.
Either that, or submit your manga to some contest that Tokyopop or Kodansha is holding. Just be sure to follow the guidelines on how to properly submit your work, and cross your fingers
best of luck to you.