Oil Vs. Butter or any other fat

[chellebaeby]

I like baked goods but I want to use canola oil instead of butter or any other oil product because it is better for cholesterol levels. My cholesterol dropped 100 points just by changing oils. The recipes I have made using canola oil always come out good and moist. Does anyone know the correct ratio to substitute canola oil for butter? I am trying to make cookies but I do not know how much oil will be sufficient to make the a success.