DVDStyler
Quick and Fast: A very good alternative to Adobe Encore, Sony DVD Architect and other burning programs. Good stuff!
Where to get it: http://www.dvdstyler.de/ Windows/Mac/Linux (as far as I can tell)
I like DVDStyler better than DVD Flick. It took a while, but I made the decision based on the fact that DVDStyler is more flexible when making menus, since you can design your own menu backgrounds and buttons in Photoshop or GIMP, and import them into DVDStyler (or simply point the program to where they are. Also, DVD Styler has a more set in stone license and is available on more platforms.
Tutorials: http://www.dvdstyler.de/index.php?option=com_content&view=article&id=46&Itemid=55&lang=en This has everything you need: wiki, documentation, etc.
License and Use: GNU GPL. You may use for commercial purposes.