Baby centipedes and millipedes

I found 3 baby centipedes (2 3/4 and one an inch) and a millipede. They are the arizona desert centipede (largest in North America) and the desert millipede. How would I feed them? How long do they live? How can I prepare them for molt? Breeding?

I don't know much about centipedes, but I do keep that type of millipede (I assume you're talking about Orthoporus ornatus). This caresheet covers the general basics of millipede husbandry http://www.arachnoboards.com/ab/showthread.php?263344-Cavedweller-s-Basic-Millipede-Caresheet The only difference with O. ornatus is they need more ventilation than most millipedes, which means extra airholes.

Along with leaf litter and rotten wood, I've found that O. ornatus is particularly fond of carrots. You don't need to do anything to prepare for molting, it will probably vanish underground for a few weeks when that happens, though I did have an O. ornatus molt aboveground once. As far as I know nobody's managed to get this species to breed in captivity. I'd guess they live 5-7 years, I've had mine for 2 1/2 or 3 years, they were adults when I got them, and a few have died off in the past year.

Good luck!

Also, the other two are actually very small, only 1/2 of an inch. Should I feed them hydei fruit flies? And can miraclegro soil be used? It is organic. Can you respond?

You mean the centipedes? I don't actually know anything about centipede care, but I'd imagine pinhead crickets would work. Don't use miraclegro, or soil in general. Millipede substrate needs to be mostly food material (dead leaves/rotten wood).

Can someone answer for centipedes? Also, thank you for the tips!