We're down in Florida, but the basics of Scouting anywhere is pretty much the same. Cub Scouting is an offshoot of the Boy Scouts, like Brownies are the offshoot of Girl Scouts.
Cub Scouting starts in 1st grade (age 7)-- Tiger cub
2nd grade (8)-- Wolf
3rd (9)--Bear
4th (10) and 5th (11)-- Webelos
Tiger, Wolf and Bear all wear blue shirts and pants/shorts, different colored hats and neckerchiefs (depending on rank). Webelos are green/khaki.
To get rank, they must complete achievements. For example, Tiger cubs have to do 5 "go see its", 5 family activities and 5 activities in their den.
Dens are what the boys are in; lead by a den leader and assistant leader. Pack is a group of dens. Heading the pack will be a Cubmaster, Assistant CM, and a Committee (here, made up of committee chair, treasurer, secretary, advancement chair and den leaders). Tiger, Wolf and Bear are mostly family involved; Webelos are less so. Webelos can camp without their families, the other ranks cannot (here anyways).
Here, the Scouts are sponsered by a business, a school or a church. Our pack is run through our church. We have to not only follow the BSA rules, but the church rules as well.
To find a pack, contact your local council. Get several options from them, and check each one out. You do not have to go to the pack that "services" your area; we live in one council district, but are involved in another. Each pack is different, you will want to find one that meets when you need and does activities your son will enjoy. Our pack, we meet weekly and camp 4x a year. Other packs do more frequent campouts or meet biweekly or (in one case) meet 2x a week!