Here's some tips to help you get the best final results.
Adobe has their own pixel sizes they recommend for SD video, but I noticed their sizes always leave pretty noticeable unfilled edges to the left and right of the screen. So I spent quite a while experimenting to come up with my own values to use for SD.
4:3 (NTSC) — create and save square-pixel images at 726 x 534
16:9 (NTSC) — create and save square pixel images at 874 x 480
Note that these are for if you're creating a DVD in Premiere Pro. They do not apply to HD sizes. For HD, create your stills at the same pixel dimensions as the video you're creating.
Since your video is 1920x1080, sharpest results would be to create your still images to those exact dimensions so they don't have to scale up or down to the video size. I'm going to base everything below on 1920x1080 HD for Premiere Pro since that's the size of your video. The DVD part comes later.
Also, save your still images as uncompressed TIFFs. Do not at any point use JPEG, which is a compressed, lossy format. You'll already be losing enough detail with MPEG-2 for a DVD, and MPEG-4 / H.264 for HD for the encoded final video without compounding the detail loss by using JPEG stills in your video sequence.
Another very important thing to do with all of your still images is to prep them for video. Most people use either Adobe RGB or sRGB as their default working space in Photoshop. Neither of these works worth a darn in video work. The color on the final disk won't display color you would expect to see on your HD or standard tube TV when played back. It will either be anywhere from oddly desaturated to wildly over saturated color. So when you have all of your still image prepped as far as size and crop, run them all through an Action in Photoshop so they're video ready.
Highlights are particularly susceptible to weird translations when the embedded profile is not a video color space. Worse if there's no embedded profile at all. So the first step in the action you create is to actually darken the full on white highlights. As dumb as it sounds to flatten the specular highlights some, believe me, this works and produces a better final output. Create a curve like this in your action:

Apply the curve. Note that I have my curves based on Pigment rather than Light. If you use the default setting of Light, then your highlight move would be from the upper right corner for the same effect:

Also note that I added an extra point to lock the shadow end some so it isn't a straight line adjustment.
The next step in your action is to convert the image to a video color space. For HD, use these settings:

Save your Action. Then use the File > Automate > Batch function in Photoshop to apply the same two step Photoshop Action to all or your still images.
You don't have to size your images ahead of time, but then make sure "Default scale to frame size is on in Premiere Pro's preferences before creating a sequence:

Otherwise, oversized images will come in centered to the frame size, chopping off the extra, and undersized images will be centered, but surrounded by black space to fill the area where you don't have enough pixel dimension in the still images or video footage for the chosen video sequence frame size. With it on, anything placed in the sequence will be scaled to fit as best as possible.
If everything is at 1920x1080 beforehand, then there's no need to have this check box on and nothing will be scaled, which eliminates another point where you would soften the image quality.
Okay, you're ready to create your video. Create a new video project and select your HD sequence preference as shown:

Click OK. The main work screen will appear. This is when you go into the preferences and turn the check box on for "Default scale to frame size" if your images and video are not already all already at that pixel size of 1920x1080. For the stills you create, resolution means absolutely nothing in video work. Doesn't matter if they're 72 dpi, 300 dpi or any other number. The only thing that counts in video is their actual size in pixel height and width.
Create a sequence and build your video, apply transitions where you want them, extra sound tracks, etc. Save your Premiere Pro project.
On to Media Encoder. Open that and add the Premiere Pro project you just finished. Since what you actually want is a DVD, you can create one from your HD sequence. All DVD video is squashed (scaled) in the height, so you're going to lose image quality no matter what you start with, which will be compound by the bitrate you use, and the MPEG-2 encoding. Since the final encoding needs to be for DVD, chose that in the left column. Make sure you specifically choose MPEG-2 DVD, or Encore will encode the video sequence again.

I use these settings for best quality DVD video, though you may need to adjust the bitrate down to fit the final video and audio on one 4.7 GB DVD:

Extra screen shot of the Video settings since you can't all of it at once:

Under the Audio tab, make sure to use Dolby Digital, or Encore will re-encode that, too.
Now, just to add to the confusion. 🙂 You can skip Media Encoder entirely and drop your finished Premiere Pro sequence into Encore. Then apply the encoding options you want there. It's up to you, but you have to sit through the encoding either before building the DVD in Encore, or after.