Check out Evie S's post on the beginning necessities for oil painting! Click image for link. Evie S tells how to clean your brushes and get your paint to flow without using toxic thinners and solvents.
I don't know much about oil painting - I have vague memories of oil painting at some point when I was a kid. My grandma did a lot of pen&ink and acrylic work but occasionally she got out oil paints. And at some point, I had a cheap little set. But it just didn't stick. Maybe it will stick with you! Go try it!