gavra_at_work-
For small kids, I would say there are two prerequisites:
I would look in these categories;
-Indian-head pennies. These are not very expensive (about a dollar each in decent condition for non-rarities) and the Indian adds an exotic flavor to the coin.
-Buffalo nickels. Cheap (about .50 – .75), and also very exotic-looking with an Indian on the front and a buffalo on the back.
-Steel Lincoln cents. Produced in 1943 to conserve copper for the war effort, these are the only U.S. coin that can be picked up with a magnet.
Obsolete coins-
-Commemorative half dollars. Produced in large volume mostly in early-mid 20th century. Prices vary greatly, depending on the coin and its condition. Mostly too expensive for kids.
(I got a little carried away, and included some coins that are not for kids)
Also I don’t feel there is any reason to get coins graded if they are for collection (as opposed to value/sale) purposes. Do you agree/disagree.
You will pay a grading fee to PCGS, NCG or any other grading service you send your coin to. You may not like the grade they give it. They may not even encapsulate it if they feel the coin was tampered with (tampering is an unfortunately common occurrence).
Nonetheless, the authentication they provide and the protective encapsulation they put the coin in may make it something worthwhile even for a collector who has no interest in selling it. Plus, if they ever are sold, an authenticated coin is a lot more saleable.