Congratulations! It's awesome being able to have your horses at home.
I can't say our methods are "the right way" to do things, but I can tell you what we do.
We have about 40 acres, 18 of which are in grassy pasture. The rest are just rocks, sagebrush, and juniper trees. We hay the grass in spring and then turn out the horses after the first cutting, usually around mid-June. The pastures are split into three sections and we rotate the three depending on what the grass looks like. We also irrigate starting in spring until fall when the temperature drops to where the grass doesn't want to grow anymore. If the horses look too fat, we turn them out during the day and then put them in the dry sage sections overnight. There's a little grass that grows there, but if necessary we give them a little clean, low-quality hay to keep them occupied overnight. I definitely recommend soil and feed tests - it's nice to get an idea of what kind of feed you'll have available.