Kathy fron Chicago Title shared this nice document about "Who pays for What in Escrow?" The same is attached for Northern California and is very useful when you look across county lines.
Q) How to know when your loan will be paid off and how much difference an extra payment will make?
A) Use a Loan Amortization calculator like the one below. You can play with numbers and see the massive difference 1 or 2 extra payments every year makes.