Read the manga, then watch the anime?

We've had a few articles on the blog about anime that's based off of manga, as many of the features are.  It seems to be the standard level of progression for a popular manga in Japan.  You know you've really made it as a manga creator if your series gets optioned for an anime adaptation!  Then it's on to even bigger and more popular things, like movies and localizations!

That's jumping the gun a bit though.  I'm looking to talk about both manga and anime due to a situation that I'm having.  If you saw our recent post about the Blue Exorcist manga, you know I'm in a bit of an interesting situation.  I wasn't expecting my girlfriend to go out and pick up the Blue Exorcist manga, and now I have to decide when I should actually read the series.

I had intentions of letting the anime adaptation come out stateside and watching that all the way through.  Then if I liked the series enough, I'd read the manga that it was based off of.  It's always interesting to see how adaptations go when moving from print to animation.  Obviously some things have to be cut and tweaked along the way, but sometimes it's quite surprising to see just how much changed in the process.

Now with Blue Exorcist, I'm questioning what I should do first.  I usually watch the anime and then read the manga if I like the anime enough.  Technically I should be reading the manga and then watching the anime if the manga interested me!  What do you guys do with manga to anime adaptations?  Do you read and then watch, watch and then read, or just do one?