Welcome to the forum
Personally I have never tried to convert Video to DVD but I am 100% certain ImgBurn is not what you need for the conversion process. A Google search would probably be the best thing, I seem to recall a program called "ULead VideoStudio" that might be what you are looking for, but as I said I have never done it myself......
Once you have your video converted to dvd compliant files, vobs, bup, ifo's or iso's then ImgBurn is what you will need to actually burn it to blank DVD?R or DVD+R Dual Layer depending on the size of the project. Check out the Guides section below for help with that stage....
http://forum.imgburn.com/index.php?showforum=4