There's a lot to learn about DSLR cinmeatography in particular. It's great that you've been doing a lot of research, but shooting with a Canon 550D is going to be tough. Unfortunately for excellent results, you can't just pick up the camera and shoot.
Everything is going to be manual focus, there are tons of lenses to consider, stabilization and a bunch of other factors that come into play.
In terms of literature, I just picked up an excellent book that I give to my 2nd camera operators if they have little experience shooting DSLRs. It has a lot of information, gives you a good background on the technical side of things and even gives you some video files to play with and teaches you a bit about lighting, colour correction, etc.
http://www.amazon.com/Still-Mo...Voices/dp/0321702115It assumes you have some knowledge of photography, but goes pretty indepth if you are a first time DSLR user. I wish this book was out when I started using DSLRs for film.
Overall advantages are:
- incredible image
- shallow DOF (oftentimes overused)
- great in low light
- great contrast/colours
Overall disadvantages are:
- workflow (hard to edit files right out of camera without some sort of conversion)
- 12 minute time limit (if making a short film, this should not be an issue...you can also hit start again as soon as it stops recording)
- manual focus ONLY (you don't have the benefit of autofocus, which kind of sucks but teaches you how to pull focus really quickly)
- need other accessories to make it completely functional (shoulder rig of some kind, tripod, viewfinder to magnify image/stabilize camera)
I say go for it. A lot of people are going to try to dissuade you, because you don't have experience with regular video cameras...but DSLRs are here now. Take advantage of it and learn as much as you can. Some places you can go to learn it in addition to purchasing the book above are:
http://www.cinema5d.com/and
http://www.dvxuser.com/V6/forumdisplay.php?f=174(^ is the link directly to the DSLR section of the board)
Best of luck and if you have any questions, feel free to shoot me a PM.
Kegan