It really depends on how you want to go about it. Greyhawk has hundreds of deities, as does the Realms. Dragonlance has only about 2 dozen, and Dark Sun doesn't really have any. Your setup is particularly well thought out, but I would suggest a few minor changes:
8 Overdieties - This works pretty well, but I would just consider them the Greater Gods, because that's how you describe them. I would try to make sure that their alignments are fairly spread out, or perhaps just unaligned (since they are above such things). In general they probably won't have much in the way of direct followers, but they may receive homage in the temples of the 32, since they are the creators.
32 Greater Gods - These should be the lesser gods, as they are more active with the world, having the majority of the temples. I would consider reducing this number down, because it makes more sense for there to be more of the racial gods. Swapping the 32 and 20 should work fine.
20 Racial Gods - These should be the demi-gods of your world. They probably don't have a lot of direct worship, like the overgods, except among those of the same race. There should be more of these than the 32, and might be tied into their church. They can provide spells, but on a limited basis, so there shouldn't be as many clerics/druids/paladins/rangers as the others.
I would organize your religions as such: the lesser gods hold the majority of worshipers, but each of these religions also offers worship to a greater god, plus one or more demi-gods. The specifics of the demi-gods could also be regional, so a demi-god may not be worshiped in all areas. This way allows for each temple/church/religion to provide information on multiple deities, which helps expand knowledge to your players.
To provide the information to the players, I'd suggest you have only 2 or 3 religions in your starting area. Provide them with the details of those religions, which should provide somewhere between 6-15 deities to start with. You could also detail a few other religions where are foes of the local religions, but that information is less specific. As you expand the campaign, you can add in new religions as desired.