Yes its quite possible, just google DVD to AVI and I'm sure youll get a heap of software to choose from. The best I know of is Moviejack in conjunction with Any DVD.
Well if you mean to burn a DataDVD to CD then you can but you'll have to break it up (obviously). If you're dealing with a video file then you can burn it in DVD format (i.e., miniDVD) but you'll be limited to ~21minutes each