I've been TVless for the last 18 months. I bought a TV 10 days ago.  
Hi sense 42" LCD 1080p 60hz on clearance from wallyworld. I knew I would be working on Thanksgiving/black Friday so I jumped on a decent price last week.

I've also got a sony bluray player and really old Xbox 360

I just got the TV mounted on the wall. Looks great

Only problem is it seems to be automatically set on 480p.

What other settings or things do I need to change or adjust to get the most out of the TV?
Anything else I need to know?
Thanks

it maybe showing 480 because unless you get a hd receiver with your dish or cable usually at additional cost, or use a antennae to pull a hd signal thats all that will come out. now if you have that already thats another story.

hook the blu-ray up hdmi, if it did not come with a cable buy one of the $3-5 ones, not the $40 ones. you can order those online, or maybe get one at brandsmart, frys , microcenter, tigerdirect

Don't have cable/satelitte so speaking strictly about bluray.

I've got 2 HDMI cords. Using one to hook up the sony bluray to the TV

The res is either in the TV or the Blu-ray menus,you either have to read the books or search on the remotes .