Secret Dreams: Oil Painting

Pleinairimage via ktmerry.com 
I have a little secret to share. I want to start oil painting.
I picture it feeling something like this photo. Fresh, natural and relaxing.
But I have no idea how to start. What kind of oils do I need? What about supplies?
Not sure if I want to take a class because I have paintings in my mind and don't want to paint someone elses dream. You know?
But maybe I need some basic instruction…or should I just dive in?

I know there are some very talented artsy folks who might be reading my little blog. Do you happen to have any advice for a wanna be artist?