The individual stamps are all portraits, with the same color background being used for each athlete from the same sport. The issue featured baseball and football players, golf and tennis stars, swimming champions, boxers, race drivers, aviators and horses. The Kellogg company issued the stamps in 1937. There are 24 panels or "sets" and 6 of the stamps are printed on two different panels. Each mini sheet has four stamps and is accompanied by a yellow margin at the top which identifies them as Kellogg's Sports Stamps and the "Set No" in a red circle to the left. The back of the sheet of stamps carries advertising for the set.
In addition to giving the basics - four stamps per package, and enumerating the various sports, you're advised that for a box top and 10 cents you can get Kellogg's Album of American Athletes and Games. The album was available by sending the 10 cents and a Pep box top. The front cover of the 12 page album advertised "5 Thrilling Games", and contained pages to glue or stick the stamps in.
As Leon said, the complete panels are much more valuable than single stamps. Here is one of the panels with Red Grange.
