Identification of flora and fauna

Our new tank continues to amaze us -- two weeks into live rock, we are
seeing new things every day and have no idea what they are. Can anyone
recommend any easily available references which can help identify all of
these tiny flora and fauna popping up all over the tank -- last night we had
a small conical shell trying to crawl up the protein skimmer ( it has now
settled into a hole in a rock) and what looked like a tiny crab poking a
claw out of a hole in a different rock.

Thanks all

Phil Krasnostein