I have this tv too, and love it, so I'll try answer.
For contrast/etc its better if you read the Home theatre FAQs, then read them again, then again, etcetc. They answer pretty much everything. :-)
As for changing resolution, I dont know if you can? I think its controlled by the device outputting to the tv. IE the cable box has several conversion "methods" that allows you to decide if you want 720p or 1080i, etc. Although I could be wrong on this, maybe its mentioned in the FAQs, I cant recall. :-)
I love my 44hm85, hd looks so freaking awesome on it..