Your slides will likely have some surface dust.
You can buy cans of compressed air.
A very brief blast of air on each side of each slide will get rid of that.
Slides to DVD.
I assume you want to create a DVD that you can play on a set-top DVD player that is attached to your television set.
You need slide show software.
If you want to do a first class job of creating a slide show, with background music and possibly narrate in the foreground, get a full featured slide slow program.
I have been using Proshow Gold by Photodex for several years.
You can download a full functioning trial copy, to see if you like it.
You can also do a Google search for "slide show software" and find hundreds of slide show programs.
I have found that 8 to 9 seconds is enough show time for each slide.
But that is adjustable for each slide. If you have a long narration, you probably want to keep the slide showing for the duration of the narration.