Hello everyone,
Let me first thank everyone here - I did not expect so many (if any) replies. Sailing folk look to be warm people, open to help.
So, conclusion from all your advises is: just do it, will be fun. And for the amount I plan to stay within (10-20k), the risk is not so big. Next step will be to find a boat in the spring, and send one-two of my sons on sailing course - or we can learn it ourself, what will better fit our style.
Lake Ontario or especially Champlain will be probably the best place to start / learn, and the world is ours after!
Best wishes everyone, and hope we meet somewhere!
Merci bien tous le monde, et en espère qu'en se croise dans un port!