Barnyardfun,
Keeping a cow is pretty much common sense... There really aren't hard and fast rules. Each person is different as well as each cow.
When your cow has her calf, you can either leave it on for a few days or pull it right off and start milking. The milk will be really thick and yellow for the first few days(colostrum) Freeze a couple of quarts of this if you start milking right away. It's vital if you get bum calves and can save puppies and baby goats too. We start drinking the milk when it thins a bit(usually 4-5 days). There are probably still some antibodies in it, but we don't mind.
Once you start milking, you have choices there too. You can milk twice a day, or you can leave the calf on during the day, lock it up a night, and milk in the morning before turning the calf back on her. You will get less milk leaving the calf on, but most families find it hard to use ALL the milk a cow gives anyway.
Keep an eye on your cow. She will look boney anyway, but if she looks like she's really losing weight, feed her a bit more. Make sure she ALWAYS has water. A good producing cow can drink 30-40 gal a day. She will tell you what she needs, and since you are milking her, you will be spending a lot of time with her and will get to know her quickly.
For the first year of calving, I like to give my cows a good 90 days rest before they calve. They are usually still growing themselves so it's nice to let them have the rest. There is also nothing to say you HAVE to milk all that time. Sometimes I only milk for 6 months. When they are older, it's good to give them 60 days so they don't get too calcium deficient and can build up some reserves.
Believe me, you'll know what to do when the time comes. I always joke to my husband that I spend more quality time with my cow than I do with him. You will get to know her very quickly and none of this is too complicated.
Good luck
Sherry