Ok, I'm going to start building my coop and run and was first wondering what is the smalles that I could go for 1-3 chickens.
Get 3 chickens, not less -- you can't have just one, it would be too lonely (even 2 are kind of lonely, frankly) and with just 2 you have the problem that if one should die then you HAVE TO get a replacement but the survivor is unlikely to get along well with it and then you'll have them fighting and pecking and all that. Whereas 3 gives the hens a more flock-ish social environment and gives you a bigger margin of error vs Sad Occurrances.
Most people seem to wind up getting more hcickens, though, once they get to know them. So unless you are legally restricted to just 3 chickens it would not be a terrible idea to build your coop larger. Alternatively, maybe build a portable thing for now (tractor, or small non-fixed coop) and then see what happens, if you don't mind the possibility of having to build something else later.
For 3 chickens in a typical climate I would not go any smaller than 3x4 coop plus a run 2-3x that size.
Also, what is the best way to protect from predators? I have some racoons, wild cats, and hawks in my general area and don't wan;t my chickens to get eaten.
A strongly built coop, with hardware cloth strongly attached over every opening (windows, ventilation openings) and raccoon-proof latches; and a strongly built run with small heavy-gauge mesh and a roof or top of some sort (preferably at least 2x4" heavy gauge wire mesh, well supported by the wood structure of the run) and either bury some more 2x4 wire mesh under the run fence or run 2-4' of that mesh horizontally on (or just under) the ground around the edge of the run.
Rats and mice will still get in, if you have lots in your neighborhood -- if they're a problem, you might have to try to rodentproof the coop and keep the food in the coop (in which case I'd strongly suggest planning a somewaht larger coop)
Remember that raccoons etc can go right through any kind of netting and any flimsy wire such as most modern chickenwire.
Good luck, have fun,
Pat
