I would agree with everyone that "getting out there" is the best way to see if you like it. You may not like racing but you can get the feel of a boat
knowing you don't have to be in a race or with the people you meet. Then again you may like it alot. I don't race our boat
but I like to go out with some neighbors that do for Wednesday night races once in a while. Boating
people do tend to get along with other boating people. Our Yacht club is half power boats and we all get along just fine.
Starting with the ASA
(or US Sail) courses I think is worthwhile if you decide you do think you like it. It can be frustrating if you don't start off with the basics from an instructor. It just helps you start with the best habits in mind. We took the ASA Baisic Keelboat class and it was 2 nights per week for 3 weeks plus the home study on the book related materials.
If you expect to sail with your wife or girl friend (not both at the same time) it's not a bad idea to see if they like it and take the class with them. I did that with my wife and it helps a lot. The captain
never sleeps when the Admiral is unhappy. It makes certain you both like and adds a degree of comfort knowing how things work
and working things together. It matters a lot more than you might think.
All your skill with power boats is most helpful for a lot of the things really are the same especially if you expect to sail the Great Lakes
. All that experience will clearly be a big boost towards getting you sailing sooner.
Perhaps the one biggest difference is with a power boat
you are going some place and with a sail boat you are already there. I know you can find a lot of assitance here too.