Follow the instructions in the little book that Dolmar wrote that accompanies the saw. You probably don't want to cowboy it for the first few hours. Check and make sure everything is nice and tight and you know how the controls work, how to start and stop the engine and the chain. Get some safety equipment if you don't already have some. Lastly, if you are new to felling, etc. get some instructions from a persion with some experience in this. You can badly hurt yourself if you don't do it properly.
Without a tach is isn't easy to mess with the tuning so I'd stick with the factory tuning. If it is missing when it has been run for 10 minutes you might attempt to smooth it out. It is probably best to let the pros at the dealer do it for you though. My saw is tuned slighty to the rich side. I think that is so if my air filter gets clogged the saw doesn't lean out and damage itself.
Get some good engine oil, blade oil, and some spare parts, plug, filters, chain, scrench, etc.
Being from Big Sky country you probably know all about this stuff.