A DVD normally had just 2 folders, an AUDIO_TS & VIDEO_TS folders (some have JACKET_P folders as well). Just create a new folder called, say, PICTURES and just drag it across when burning in Nero or whatever.
As for seeing them on a DVD Player, your out of luck. You player will see the VIDEO_TS folder, then conclude its a DVD and start playing it and not allowing access to the root folder of the dvd. They would be accessible from a PC of course. A JPG file can be imported into most authoring progs and treated as a movie, normally defaulting to 5 sec. You could just load them all in and make an extra button to them in your menu. You will only be able to addin 98 of them though as a DVD (and CD) can only have 99 tracks.