Assuming that you are at the very beginning:
1.) From the time you stop making your Mortgage Payments, you will have about a year until the Bank begins the Foreclosure process. (They won't even talk to you until you are at least 3 payments behind, If you assure them that you are trying to get your "ACT" together, they will give you more time.) (If you want to try to do a Loan Modification, they may work with you and postpone your Foreclosure.) (If you want to do a Shortsale, they will wait 1-2 months while you find a Realtor and List the Property. In the meantime they will ask you for a HARDSHIP letter detailing your hardship. They will then postpone your Trustee Sale indefinitely.)
2.) If you have done #2 or #3 it will now be 1 1/2 years later. Everything has failed and you have received a letter telling you that the Trustee Sale is scheduled for Sept. 1st.
3.) The house probably will not be sold at the Trustee Sale, but that marks the end of the Foreclosure.
4.) The Bank will send a Realtor out to talk to you: He will offer you Moving Money, $1000 to $3000 for a timely move with no damage to the house. You will have 30 days to move and the money will be given to you AFTER you have moved.
I hope this explains thins to you.
Good luck and may God bless