Perhaps the most well-known attraction in the Roseburg area is Wildlife Safari, a few miles away in the smaller town of Winston. Speaking from personal experience, this is fun for kids and adults alike. Here’s a story from the Mail Tribune newspaper’s Joy magazine about it: http://www.mailtribune.com/apps/pbcs.dll/article?AID=/20070620/JOY/706200302&cid=sitesearch
There’s also the Douglas County Museum of Natural and Cultural History. And you’re very close to the Rogue-Umpqua Scenic Byway, which as the name implies is one of the most scenic drives in the region, with numerous waterfalls to see along the route.
The Roseburg area has become a major player in wine grape-growing in Oregon, so there are lots of opportunities for wine tasting if you’re so inclined. Another adult form of recreation is Seven Feathers casino and resort, about 30 minutes away in Canyonville. It’s a main venue for musical acts, comedy shows, rodeos and the like. There’s also a new spa at the resort.
Like other Southern Oregonians, residents of Roseburg spend a lot of time in and around a major river, the Umpqua, which has rafting, fishing and jetboating opportunities.
I would suggest consulting the community calendar published online by the Umpqua-News Review when you get to town: http://www.nrtoday.com/Entertainment/Calendar.