One of your first stops in Strasbourg should be the tourist office. There are two in the city: one at the train station and another near the Cathédrale in the historic center. Both have a good supply of information and a friendly multi-lingual staff. Make this your go-to source for current events, new sites, and general information.
Consider buying a three-day Strasbourg Pass. The cost is 21,50 € per adult and 10 € to 15 € for kids. Each pass offers three consecutive days of free, half-price or discounted prices on entrance tickets to many of the best attractions in the city.