ok I have about 3 gigs of pictures I wanted to backup to a dvd-r disc using my dvd-rw. I know how to backup dvds etc but I cannot figure out how to save a iso of this 3 gigs worth of files on my HD for burning later to a dvd-r.

recorder>choose recorder>image recorder and then burn.

You do know burning these dat files, they wont run on a DVD player right?
Here's a tip, if the dat files are vcd, you can use SVCD2DVD to make dvd complaint files, or a working VIDEO_TS FOLDER FOR PLAYBACK ON DVD PLAYERS.
www.SVCD2DVD.COM
Exellent program. It does not reencode the video file so no quality is lost, it merely resamples the audio portion to 48000 Hz which is required to fit DVD spec.

if they are just picture why make an ISO file? just make a data DVD and drag the pictures over to the dvd and burn?

it is no diff then burning a data CDR - i do it all the time.

Download MagicISO, it is a good ISO creator. Use magiciso to make dvd iso image and burn it onto dvd.

http://www.magiciso.com/tutorials/miso-overview.htm