In most cases the borrower is the responsible party to make the payment for the appraisal service. Check with your Lender to understand if you are to pay in advance for the appraisal, if the Lender is going to include the fee into the loan costs, or if the Lender is going to cover the costs. Payment will be made to the appraiser for the completion of the appraisal assignment and in the case of a cancellation many times a research fee or trip fee will be owed.
Once the appraiser arrives they will most likely want to start on the outside of your home. The appraiser will take exterior pictures of the home and additional features. While outside they will begin to take measurements of the home. They will be completing a sketch of the home which will show the dimensions of the home and the floorplan layout. Some measurements may need to be taken from within the home in the case of multiply story homes and/or condominiums.
If you made an appointment and need to reschedule contact the appraiser and/or the appraiser's office as soon as possible. If you have decided not to proceed with the financing contact you Lender immediately and then reach out to the appraiser to inform them of the change. A fee may be owed depending on the amount of work that has been completed. The appraiser will typically have performed much of the research and report preperation prior to the inspection and if the appraiser is en route to your home or has inspected/observed your home there will be a fee referred to as a "trip fee" owed. This fee is typically less than the full cost of the appraisal.