David
Yes to your question. Make them JPG, TGA, or PNG files.
Attach your camera to your network or use a PC to transfer them to your switchers USB.
I would make a folder called "Camera Pics" or something like that on the root of the switcher USB.
You can program the switcher to load them into your media store, OR you can use dashboard and drag and drop them to the media store (live- if you want to).
As far as pixel and dimension... I always shoot 1080 HD quality, If your show is lower resolution such as 720 then it will auto adjust down and look great -- if your show is 1080 and you shoot in 720 then it will auto adjust to the 1080 output, but the quality is going to be a little less than if you shot natively 1080.
Hope that helps,
Gordon
#Carbonite