A few years ago, my wife and I stayed there for a 3 night stay during the 4th of July holiday and then moved to the Lake Granby/Grand Lake areas to finish up the week. Steamboat Lake S.P. is about 25 miles north of town and it's a beautiful area for sight seeing, hiking, fishing, boating, etc and it's really not that far from town should you find that you forgot something. If I remember right, we stayed in the Arnica Loop.
Just north of there is Routt National Forest area and you will find a ton more "off grid" type sites if you want that kind of camping experience while you're here. Here's a link with more info if you're curious - http://www.forestcamping.com/dow/rockymtn/rout.htm
Another campground that you might take a peak at while you're in that area is Stagecoach State Park, which is about 15 miles south of Steamboat. I've never stayed there, but many of my hunting/fishing buddies have and they tell me that they prefer it over Steamboat Lake just because it is closer to town, less traffic, and better fishing.
Enjoy your stay, there will be plenty to do.
Where we've been:
2000 Rockwood Roo M-18 Hybrid
2006 Dodge Ram 2500 Auto 5.9 Diesel
Gone but not forgotten -1986 Rockwood 1003 PUP