Curious About A Type Set

It regards collecting specific set of coins in a series, a collection of types, or a collection from a particular Mint. This would include such sets as a complete series set (Lincoln cents from 1909 to date); a type set of gold coins or a branch mint set of quarters.

If you have a Red Book. There before each denomination is a price chart for type coins.
For example you could simply have a US nickel type set too.
That could be 4 coins, or to be more specific, you could have varieties within the types.

1866-1883 Shield nickel
1883-1913 Liberty (V) Nickel
1913-1938 Indian Head (Buffalo) Nickel
1938-Present Jefferson Nickel

or

1866-1867 Shield nickel with Rays
1867-1883 Shield nickel no Rays
1883 No Cents Liberty (V) Nickel
1883-1913 With Cents Liberty (V) Nickel
1913 VAR 1 Mound Type Rev Indian Head (Buffalo) Nickel
1913 VAR 2 Line Type Rev Indian Head (Buffalo) Nickel
1938-Present Jefferson nickel
1942-1945 Wartime composition Large Mint mark Jefferson Nickeland so forth

There are albums set up to fill certain holes for US type sets and other countries as well.
You can make up your own type sets. That's what I am doing.
Here on our very own site is a handy page of which you could choose which coins you can afford to try and fit into your set.

http://www.coincommunity.com/us_coin_facts/

Type sets are usually a work in progress, always getting an upgrade here and there or when we get lucky a new addition we didn't have. They seem to never be completed but mostly always improve.
If you have change in your pocket, you are on your way.

That is a nice looking album! Your digital type sets are impressive as well.