What softw do you have? Do you have iMovie & iDVD? Do you have Toast 6? You can do it using any of those programs. It helps though if you have QT Pro. In any case, import the video into iMovie & then add whatever markers you wish. Then swap it over to iDVD. It's something like that. I haven't used iDVD for a long time. Try it out on a DVD-RW 1st so you can learn bit by bit to improve on your efforts. Also with Toast, it should be able to import the QT clip & it will convert this to mpeg2 before burning. Personally I use Final Cut Pro & DVD Studio Pro. But these are not cheap programs. And they're built for dummies so to speak like iMovie & iDVD are which are too easy to use. (Xcuse the word but you know what I mean. lol
) You can add menus (iDVD has a lot more control over menus than Toast & some pre-made ones are very impressive! You can add sound to the menus also.)
avatar: Go to user control panel (click user cp button above), & select Edit Options tab. Then down bottom of page you'll see avatar options. You can select one or make your own but it must be a certain size.