What FoxHunter said.
Pretty much you want to have different forks/wheelbarrows/halters/gloves/clothes/hay/hoses, etc.. when working in the quarantine area. Everything should also be bleachable.
Bleach is good for killing stuff, but Virkon is better. It's majorly cheap too, I highly recommend everyone have some in their tack room!! I spray down everything that my horse comes in contact to. At shows I do his stall, etc.. etc.. As well you'll want to clean out and Virkon your trailer after transporting the new horses.
With the worming, yes worm them immediately and get them vaccinated as soon as possible.
A 21 day period will cover the incubation period of most diseases.
Good luck! Quarantine is fun! (Not.)
They say money doesn't buy happiness -- well happiness doesn't buy horses!