Chook chick and Pat had good tips and I saw others too.
First off, hit the books to learn what NOT to do in construction and carpentry.
Evaluate your tools and skills situation realistically.
Decide what you want from chickens, meat or eggs or both. Build a little oversized if at all not sure.
Do allow 4 sq ft/bird inside and no less than 10 sq ft per bird outside in run and since you have a mini farm, make a really big oversized run.
Do plan to run both water line and buried 20 amp line to it. You will be forever glad you did. And do both BEFORE you start building.
If that is also new ground, hit the books on the plumbing and electrical work. If you cannot do the hook up, do all of the prelim rough-in work and then farm out to a plumber. Ditto for electrical. Bury both lines in same trench the same day or soon after you rent trencher to dig the trench.
Consider a frost-proof hydrant near to coop site. You will be glad you did.
Do not neglect ventilation, and put permanent ventilation at top of wall height. I did 1 sq ft for each of my 4 chooks. I did a turbine vent in center of roof.
Do not underestimate predators! They are patient and crafty and in synch with Murphy's law.
Work safely and take lots of breaks.