Here's a quick guide on using the new Nero 8 to burn DVD-Video. For this guide will use Express.
In the Start Page click on 'Rip & Burn'. By default if you click on Burn Video Disc - Burning Rom will open. To change that move your cursor over Burn Video Disc and right click. Here you can change what app of Nero you want this option to open. Or pick one in the list. Here I picked Express.
Once you click on Express - Express will open with the Video option picked. Now click on DVD-Video files to add your files.
Click add, find the folder that has the movie/video and click add.
Now your files are added so just click next.
Here you can name the dvd, pick a different drive to burn to, and set your burn speed. Burn at 1/2 the rated speed of the media. Click Burn and Nero will start burning.