Research. Learn. Talk to other Sibe people. They are not the pet for everyone. Their looks should not be the key factor you want one. Plan for it. Make sure your Sibe is a fit with your family. Make sure you find out everything you can about Siberians, and prepare as best you can before you bring one home. I say "as best you can", because you will probably never be PERFECTLY prepared. You will always still find something new to learn. And so will your Sibe. Things you must be prepared for:
This is a talkative dog, for the most part. If you're looking for quiet, keep looking.
This dog is SMART. There are times when you will swear he is smarter than you. You always have to be five steps ahead.
NEVER, EVER, EVER let this dog run off-leash except in an enclosed yard or dog park. To do otherwise is a recipe for disaster.
This dog wants to be part of the family, just like any other dog. If you're going to stick the dog out in the backyard and leave him alone, or keep him in a crate for 23 of every 24 hours, don't get a dog. Get a cat or a hamster.
If you are set on a dog, and you know your dog will be your very hairy child, please consider rescuing. Secondhand dogs really do give first-class love.