I hate XCDRoast. Its too confusing. Im currently using GnomeToaster, which needs a little work to make it more obvious what to do, but otherwise is a great program. If you use it, the first side tab is for files, the second tab is for tracks and ISO files and the third is (obviously) for burning the CD. For instance if you have an ISO you want to burn, you just drag and drop it into the second tab and voila. If you have a ton of music files you want to be music tracks, just put em in the second tab. If you have a bunch of files, put them in the first. Also, you need to select your max burning speed before burning. Otherwise it will go slooooow. I haven't tried K3B. Maybe I'll get a hold of it and test it.