As a precaution I would treat them with Flubenevet for internal parasites and with Frontline (for kittens / cats) for external parasites as son as possible. Probably best to treat them with both products separately say 2 weeks apart. Flubenevet is the best wormer and takes 7 days to treat them.
In the coop use dust extracted shavings or better still a product like Hemcore which can be bought from horse supply shops. Hemcore can also be used in the nest boxes.
The perch in the coop should be slightly higher than the nest box if possible. Its worth putting an internal tray below the perch to help easy cleaning. Two trays of about 8 to 10" wide are are best butting up together directly under the perch.
Clean the coop out regularly using Poultry Shield and use Diatom especially on the ends of the perch and any crevices.
If you can move your run to various areas on green grass that would be best as they soon trash the ground. Winter time can be messy especially when wet so if you can cover the run that will help. A dust box 18" square with 6" high sides filled with compost, peat moss, coarse sand etc.. helps as they will dust in that instead of digging hollows'
Feed with layers pellets with an handful of mix corn late in the afternoon. Keep the supplied with greens i.e. cabbage, lettuce, kale, chard, spinach etc.. Obviously ensure they have clean water available taking care in freezing weather.
Ensure they have a good supply of oyster shell and grit.
I would definitely go for 3 hens and your choice of hybrids is best to start with. Once they start laying you will get about a dozen and half eggs per week in their first year.
That's about it I Think