Assembling a type collection is more than just filling holes in an album. There are the basic types to collect, such as Shield nickels, Mercury dimes, and so forth. But what to include in a type set? It would depend on how many years and how much you want to include.
I've always been a fan of type collecting. Finding one of each basic design type can teach a collector so much coin history, American history, something about mintage, metals and art. There is also the possibility of finding a new collecting interest. When you find a pretty two-cent piece, or another different coin, you may learn more about this series and decide to pursue it.