You'll need some type of video editor. Windows Movie Maker will work ok. Sometimes software will come bundled with your camcorder.
I use either Arcsoft, Sony Movie maker, or Nero, to make home movies. Arcsoft came bundled with a camcorder. I bought the Sony software, and Nero.
There is a free video editor called Jahshaka http://jahshaka.org/
Others swear by it. It won't work for me.
There is a lot involved in making a DVD, but, Basically all editors work the same. You need to move your video files from your HD to the "media Pool" in your editor. Then find the timeline in your editor, and drag Your file to the timeline. Place your files in the order that you want them appear on the DVD. Most editors will have "Transitions" that you drag between the video files. I can't go into all the details here, there's way to much to it. But, You can add text, titles, menu's and a host of other cool things.
The editor should have a "Make DVD" or "Burn DVD" feature. I would use an mpeg format because AVI's can be quite large.
and virtual dub http://www.virtualdub.org/
will both convert AVI to MPEG
For more help check out DVDHELP. http://www.dvdhelp.com/
Just play around with the video editor of your choice. (use DVD-RW's so you don't burn coasters.) if you run into a snag post back here.
Try to be more specific with your questions.
This is all from memory, as I don't use the PC much anymore. So corrections are always welcome.