Silverwood Theme Park is a great one or two-day experience.

Lodging near Silverwood 

There is camping nearby.  Across the street is Silverwood's own RV/Camping park, called Silverwood RV Park.  There are three primary advantages to camping in this park.  First, you get significantly discounted tickets to Silverwood theme park, second, you get free theme park parking, third, you are literally right across the street from the theme park, entering the park by simply walking through the tunnel which connects them.  The park has showers and bathrooms, and some very nice tent spots.  However, beware of staying in the following camping sites, because you will experience very high noise traffic from U.S. Hwy 95:  T1-T20, 55-79, 91, 93, 95, 97, 110, 111, 113, 126, 123, 122, 121.  All other sites are okay, with the following sites being prime because they are closest to the Silverwood theme park entrance tunnel:  1-20, 71, 80-83, 84-90, T23-T37.  With the combined cost savings from the ticket discounts and parking, some find that their camping is paid for with those savings. 

Another camping option is Farragut State Park just up the highway; it is a gorgeous State Park and a destination in itself.

Cedar Mountain Bed & Breakfast is a nice place for families to stay, and is also located very near Silverwood. The folks at Cedar Mountain B & B have a lot of animals, so the young kids will enjoy seeing them and exploring the property.

If you'd prefer a hotel, Holiday Inn Express in Hayden, Idaho is the closest actual hotel to Silverwood, but any Coeur d'Alene, Post Falls, or Hayden hotel properties are only a 15-30 minute drive to Silverwood. Sandpoint is also an option, but it is probably 30-45 minutes north of Silverwood. Holiday Inn Express in Hayden is connected to Triple Play Family Fun Park and Raptor Reef Indoor Water Park, so if you end up with bad weather on your trip, then that is a great place for kids as a fallback. This particular hotel, and many in the area, offer Silverwood packages. This hotel also has several family suites that offer bunk beds and larger accomodations. There is one company, ROW Adventure Center, that offers Silverwood packages that combine outdoor adventure, discounted entrance tickets and hotel stays. They have relationships with most of the region's hotels. You can find reviews on TripAdvirsor for ROW Adventure Center under "things to do" in both Coeur d'Alene and Spokane.

The Holiday Inn Express in Coeur d'Alene on Seltice Avenue is also nice and family friendly. This hotel is close to Rivertone which has a Regal theater and shopping, and is also close to downtown Coeur d'Alene and the Centennial Trail.

Silverwood itself ...

Silverwood is clean and VERY family oriented. You can do both Silverwood AND Boulder beach in one day, but if you'd rather enjoy both areas of the park, you might consider doing two days. There is also a discount if you buy a two-day pass. If you are only going for one day, check out Costco for discounted admission tickets. You cannot take food into Silverwood, but you can go in and out with a hand stamp. A lot of families pack a picnic in a cooler and then just go out to their vehicle at lunch time and picnic across the street. There is some grassy area and picnic tables, or a lot of people just tailgate. However, food and beverages are priced reasonably for a theme park. Less than the typical movie theater. There is a Pizzeria that offers decent pizza, and if you are feeding a family of four, it makes sense to go for the whole pie for about $20 vs. slices or individual servings at other places. There is also a good asian/teriyaki shack at Boulder beach that is economical for families. The servings are fairly large and you can purchase an adult meal for less than two kids' meals.

Silverwood has over 65 rides and attractions, from raging roller coasters and insane 65 mph drops to rides built just for the little ones. By the time you add in water slides, wave pools, a steam engine train, magic shows, cheeseburgers, and ice cream, you've got more fun that'll fit into just one day. It is like the old west meets modern day...