Tokyopop, being one of the few companies to embrace the potential of online manga is doing it again. Starting this week, and until Wed. 7/2/08, you can read all of Bizenghast Volume 1 on their website. And for every week after, you can read another volume leading up to Volume 5, which will be available to read on 7/15/08 only.
I got hooked on this series through reading it online. Last year Tokyopop did this for the first two volumes, for the release of the third. If you want to check out a series, reading it online is a great way to sample it. And if you do like it, buy the volumes. Online manga lets you taste the series, but having the book in your hand gives you the real experience.