Guide on adding a new model, animation, and creature to HoMMV

Regarding the icon texture, I like my screenshot. The only thing is, I had to keep the original background because my Photoshop is acting up and has a mind of its own. I used to save in PNG format without a background, but I don't know what happened; I haven't used it in ages. Now, in PNG and DDS format, it doesn't save anything, even with the downloaded plugin. So, I have to prepare it in JPEG in Photoshop and save it in DDS using xviver... As soon as I figure it out, I'll make the icon without a background, and of course, I'll add voiceovers to the animations.