Celebration is off Hwy. 192 (Irlo Bronson Hwy), basically on I-4 right across from the Mickey Mouse head power pole. It is on the East side of I-4 at the intersection of I-4 and 192.
There are some shops, restaurants and a movie theater as well as the Celebration Hotel. It's a nice little town to drive around in and look at the different types of housing, but I wouldn't get too excited about it or plan a whole day's worth of activities there.
Old Towne is also next door to Celebration. So if you wanted to combine a little side trip on a non-Disney day, you could go there as well. Old Towne has some carnival type rides and some restaurants and shops, also. It also has one of those dragster-type rides where you race an opponent in miniature dragsters. Pretty cool.