oh, and Joan recommends not feeding them bloodworms cos of their shell which are difficult to digest. Joan is a guru with these things. You really should come to the Vic Betta meets, you'll meet other betta people and learn a bunch of stuff. There's time to book a flight with Jetstar to come to the meet this Sunday.
I don't know what the others do but I feed my betta tiny 1mm Spectrum pellets, just one pellet each meal time. I'm hazarding a guess but the tiny 1mm pellets are about the size of his little stomach so I don't try and give him anymore than that each time (although I've seen him eat a lot more than that).
He sees when I'm feeding the other fish with flakes so he'll come up to me and I'll drop the little pellet in front of him and he'll gobble it up. So if all I had was the betta in the tank, there'd be no messy flakes floating around and settling on the bottom.