Energy Efficiency for Homes

[14Corolla]

I know some of you are into energy efficiency in general.
I'm interested in finding out more about energy efficiency for my home.

To be specific. I have about 18 inches to two feet of basement wall exposed on the outside of my home. How much will it help to cover that. Cover it with dirt lower. But rock higher up to the siding. When it gets below zero. It seems like those walls are heat sinks. Would like to help the home.

My garage is attached and not insulated. How much will it help to insulate the garage?
I'm a little disappointed in my garage. It only stays about 15 degrees warmer than outside. I think this could help alot.
Also to insulate at the rafters would be a big hassle. I have those vents in the eves. Also a vent at top of roof. Do I really have to have these vents in a garage? Code requires in a house. But garage?
I'm thinking my best bet is to put a ceiling in the garage. Then put insulation over the ceiling. ????

I can't say my energy bills are bad. I would like to help. I don't make alot of money. Don't want to waste money on something that really doesn't do much at all.