Tom's response is complete, and right on, though you will find differing opinions and preferences. Personally, I prefer to mill from the narrow end of a tapered log. It is just easier for me to gauge the blade height setting, and believe the blade cuts straighter through knots. It isn't worth the time it takes to turn a log around, though. And yes, I do occasionally have to grab the chain saw and trim the log if I don't pay close attention.
I prop the narrow end of the log up with a toe board (in my case, I use a scissors jack) to level the center line of the log. You'll get straighter grain and a better yield that way.
I try to keep a hatchet handy to knock off bark that has dirt or rocks embedded in it, though a chain saw also works, if you're careful.
Hardwoods mill easiest within a few days of cutting the tree down. Maybe someone with cabin building experience will weigh in on seasoning the logs. I probably average 3.5 to 4 hours milling oak between blade changes, but as Tom says, you should change the blades when they're dull. Since they dull slowly (unless you try to cut through metal), you may not notice that it is slowing down. Certainly easier to notice if you have a manual sawmill.
I live about 150 miles south of Tom, so frozen logs are unheard of around here. Any time it isn't too hot or too cold is a good season to cut. I do try not to harvest timber when the ground is soft, though with the drought, that hasn't been a problem.
Take your time, learn from mistakes (other's mistakes, if possible), keep a few extra blades handy, be careful, and enjoy the sawdust in your face!
Would love to know more about where you are, what kind of mill you run, and how you'll be using your lumber.