Is it now in dvd-video format? (a Video_TS folder with .vob, .ifo and .bup files)
DVD video isn't the best format for editing, but it can be done successfully with tools that are designed to work with it. I suggest getting the free trial of Womble Video Wizard DVD. It is fully functional for the length of the trial, which is 30 days I believe. http://www.womble.com/index.html
If it is in another format, like DV avi, then you might want to consider a program like Adobe Premiere Elements or Sony Vegas Home Studio. They also have free trials.