Basement ceiling insulation is important to keep cold air out and floors warm on first floor.

This insulation above is damaged and will not work properly.  The effective R-value has dropped from R19 to about an R5.

Rim Joist are basically an extenstenion of your main house walls into your basement. 

Cold air will quickly go through cracks and convect through the thin wood.  Rim Joist should be sealed and insulated.

Large penetrations is where the majority of cold air that will be sucked up into the home.

After foaming around all penetrations drafts, heat loss will be significantly reduced.

Closed Cell Foam

Creates a complete seal

Highest R-value

Will not support mold

Perfect for hard to reach crawl spaces with dirt floors, or where not a lot of insulation can be added

Rockwool

High R-value

Will not support mold

Non-toxic

The best substitute when foam is not available

Fiberglass

Highly ineffective

Mice and insects can live in it

Not reccomened

Fiberglass batts are highly ineffective, and are normally used as the cheapest method to meet code

Cold air will be driven into the home from the basement from what is known as the Stack Effect

Stack effect occurs because there is a difference in temperature between the inside of your home and the outside.  In the Winter when your home is warmer then the outside air, the warm air rises out of the house and draws in new cold air from the basement.  Thus its important to seal up and insulate your home to prevent the cold air from being drawn into the home.