The awesome thing about Pauper Commander is that it opens up possibilities that regular Commander doesn’t offer. Think of all of those cool uncommon creatures that just never served any purpose in Constructed decks. If you can find enough commons that thematically support it in a singleton format, go for it!
One awesome thing about Pauper Commander is that many Commander staples are in fact commons: Command Tower, Darksteel Ingot, the various Signets, and many more. The power level of cards is nowhere near traditional Commander and you don’t end up with a lot of the super expensive lists that you may find in regular Commander.
In the near future I’ll be going over some popular and powerful Pauper Commanders. While you’re at it, though, take a look at your collection and see what Uncommon creatures you may want to build around. Remember that color identity rule is exactly the same in Pauper Commander as it is in regular Commander. This means that abilities that call for different colors of mana than those in the creature's mana cost will you to play cards of those colors in your deck, as well.
For the complete Pauper Commander rules, check out the “official” Pauper Commander Website.
So who will be your Pauper Commander?