How to author a DVD (a reprise of my answer in this thread, with a few more details):
Okay, this is a little long, but I hope you can make your way through it. To put video onto DVD you need to do the following things:[ul][li]Import the video into your computer.[]Edit the video while it is in your computer.[]Add menus and artwork to the DVD.[]Create the final disk image.[]Copy the disk image to a blank disk.[/ul]Some details…[/li]
Import the video into your computer.
Fear The Turtle, you can skip this step and go to “Edit the video” below because your files are already in your computer.
If you have digital video, such as is recorded on a DV camcorder, you may be able to connect your recorder directly to your computer. Suitable software on the computer can instruct your recorder to play back its digital tape, and the video file is transferred directly to your computer.
If you have analogue video, such as is recorded on VHS tape, you will need to play it back into a “video capture device” that is connected to your computer. This device digitises the video, converting it to a video file which your computer can store. Video capture devices are available separately or as part of some video cards.
Special software and connections are needed for both these tasks. They are normally supplied as part of a video editing package, although you can use standalone software and hardware as well.
Many computers these days come with the high-speed serial connectors required for digital video input. (Thanks to competing groups of manufacturers, this connector has three different names, depending on who you ask: “IEEE1394”, “Firewire”, and “iLink”.)
Analogue video inputs, resembling those on the back of a VCR, are less common. You generally have to buy a video-editing package to get them.
Video-editing software will often communicate with the software that handles the importing, hiding some of the complexity.
*I often use the import function of my video-editing program, Adobe Premiere, to import the video, but if it’s just a few files that I don’t want to do much with, I’ll import them drectly from the DV camcorder tape through a little utility called “DVIO”.
I also use a Pinnacle DV-500 analogue capture card. It too works with my Premiere video-editing software.*
The imported video files will take up a LOT of space. Typically I require 12-15 gigabytes to store 1 hour of video. It also speeds things up to have multiple hard drives, with files on one and working space on another.
On the Windows PC, imported video files will often be in the “AVI” format. These can be recorded with many different “codecs” though. Some of them may need to be converted so that all of the files in one project used the same codec.
Edit the video while it is in your computer.
When you edit the video, you indicate in the video-editing softwere which pieces of video you want to copy from your source files and place in your final output files. Various snippets can be cut, rearranged, modified. Sound and music can be added or removed.
Fear The Turtle, all your video files will have to be converted to the same format and resolution so that they can be brought together on your final disc*. This may be your greatest unanticipated challenge. 
Simple editing software comes with many computers. Complex editing software costs bucks, but is far more flexible.
To do detailed video editing, such as transitions, overlays, etc, I use Adobe Premiere. This software comes with many video-editing kits. There are many other video-editing softwares available though, including some free ones. Look around at VideoHelp.com (see below).
At the end of the editing, you tell the video-editing software to generate an output AVI video file of each video clip. This is very time- and space-consuming.
These edited output files can be recorded to tape. If our final goal was to make a VHS tape, we would make one big output file that we could play back while the VCR was recording, and that would be the end of the process. But a DVD is more complex, and requires more steps…
Add menus and artwork to the DVD.
During this step, you convert and compress the output video files to fit on the DVD. This is another time-consuming step. The files are transformed from AVI to MPEG-2. I use the encoder “TMPGEnc” to do this.
Then you edit and add the menus and other artwork to help you navigate around the DVD. You can also add subtitles and additional audio tracks. This is known as “authoring”.
This is where different DVD-authoring software has dramatically-different capabilities.
The simple software looks at the video files presented to it and automatically creates basic menus. Complex software lets you design your own menus, import pictures, define what happens when you push the arrow buttons on the DVD remote, and specify all kinds of other behaviour.
*For authoring DVDs I started out with the simple software Windows MovieMaker and Ulead Studio, but I now use TMPGEnc DVD Authoring. This software looks at the set of video files you give it and automatically creates appropriate menus from a limited number of preset templates.
For greater control, I use DVD-Lab Pro, which I have found to the THE most flexible program affordable by mortals, in spite of the fact that it’s still in beta and therefore a work in progress. For DVD-Lab Pro, I can create my own menus in any graphics-editing program. (I use Photoshiop.) Doing the buttons by hand can be very tricky. I highly recommend using the simple software to start. *
I believe that the VCR-style DVD recorders automatically create simple menus. I’ve never used one; I really don’t know what the discs they create are like.
Create the final disc image
Once the menus and everything are in place, you create a disc image of the final DVD. The authoring software combines all the elements–menus, video, audio, subtitles–and builds a disc image according to the DVD standard. The disc image is built on the computer’s hard drive. A single-layer** DVD disc image requires up to 4.7 billion bytes of disk space, the same as the physical DVD.
Copy the disk image to a blank disk
You then burn the disk image to a blank DVD. It’s like copying a CD, but takes longer. I use B’s Recorder Gold, simply because it is the disc-burning software that came with my LG DVD drive.
There is one major gotcha though: not all DVD players will play all types of home-recordable DVDs. Some older units won’t play any recordable DVDs at all!
Different types of recordable DVDs
There are three competing camps of manufacturers of recordable DVDs:
One camp makes the discs known as DVD-R and DVD-RW (“dash” discs).
One camp makes the discs known as DVD+R and DVD+RW (“plus” discs).
A third camp makes the discs known as DVD-RAM.
-R and +R discs are recordable once only, like CD-R.
-RW, +RW, and -RAM discs are recordable and erasible, like CD-RW.
The problem arises because many older recorders and standalone DVD players will handle “plus” discs but not “dash” discs, or vice versa. Newer devices can handle all the disc formats.
You can check machines’ compatibility with different recordable-disc formats through the database search at VideoHelp.com (see below).
This format difference has nothing to do with the movie studios’ DVD “Region Codes”. Recordable DVDs available to the consumer are not encumbered by region coding or the encryption that goes along with it. The DVD you make on your computer will play on any machine that can handle your television standard.
Some resources
A good place to start learning about DVDs is the DVD FAQ:
http://dvddemystified.com/dvdfaq.html
All kinds of questions about DVD, its features, and its history, are here on one long web page. Jim Taylor, author of the definitive reference book “DVD Demystified”, keeps this page up to date.
http://www.videohelp.com (also known as dvdrhelp.com, vcdhelp.com, and svcdhelp.com) has a vast collection of DVD tips, tricks, and software and hardware ratings.
Site volunteers maintain a database of DVD players, recorders, and computer drives, searchable by model, make, feature and compaibility.
There are how-to guides on such things as how to make your home videos DVD-compliant, and how to make DVD menus. There is also information on authoring VCDs and SVCDs, the discs that preceded DVDs.
[sub]*The video and audio must be of the same format and resolution if you are making a single-VTS disc. It can vary between VTSs on a multi-VTS disc. but that’s a detail, as simple DVD-authoring software only makes discs with one VTS anyways.
**Most recordable DVDs have one recording “layer” on one side of the disc, and can store 4.7 billion bytes of data on that side. Some are double-sided and can store that much on each side; you flip them over to change sides. Just out are “double-layer” discs that can store 8.5 billion bytes on two layers on one side; these require new drives to write but can be read by most readers. [/sub]