What will you be playing the DVD on? I think you can just use disk utility for ISO (burn disk option). AVCHD is drag and drop, or you can use disk utility. Toast may also work.
If you wanted to author a DVD with menus and such so it looks like a commercial DVD, most video editors like iMovie give you an export to DVD type option for simple stuff. If you want to get fancy you need something more robust, I use DVDSP. Not sure the burner in the 2011 is DL capable.