Here is a description from the LA times. Obviously, this pertains specifically to California. While state regulations vary on what requires a notary and some particulars, in general it works.
“Job Description
A notary public is authorized by the state to serve as an impartial witness to the signing of documents, acknowledging that one has entered into an agreement knowingly and willingly.
Notary publics are used to make the document legally binding. They are not responsible for the accuracy or legality of documents they notarize. It is the signer that is responsible for the contents of the document.
The notary public verifies the person’s identity, usually done with a driver’s license, presses the notary seal on the document and signs it.
Fees
The fees set by a notary vary from state to state. For the State of California, the fee per signature ranges from $5 to $20, depending on type of notarized document. For example, when notarizing a deed or power of attorney, the fee is $10 per signature. For notarized services provided in connection with deposition testimony, the fee is $20.
Certification Requirements
State Certification requirements to become a notary public include clearing a background check and passing a multiple-choice examination. The application and certificate fee is $20. For further information, contact:
Secretary of State
Notary Public Section
1500 11th Street, 2nd Floor
Sacramento, CA 95814
(916) 653–3595
Fax (916) 653–9580
www.ss.ca.gov
Exam Services
(916) 263–3520
The following are schools in the Los Angeles County area that offer the one-day notary public exam preparation course. They give you the option of taking the exam after completing the class:
Santa Monica College
Continuing and Community Education
1900 Pico Blvd.
Santa Monica, CA 90405
(310) 434–4000
www.smc.edu
Cost: $40.
West Los Angeles College
Westside Extension
9000 Overland Avenue
(310) 287–4475
www.wlac.edu
Cost: $49
Monrovia Adult School
920 S. Mountain Avenue
Monrovia, CA 91016
(626) 471–3035
Fax (626) 471–3036
www.monroviaschools.net
Cost: $35.
Burbank Adult School
3811 W. Allan Avenue
Burbank, CA
(818) 558–4611
Fax (818) 558–4620
www.burbank.k12.ca.us/schools/adultschool/
Cost: $40.
The following professional association also offers a one-day notary public exam course:
National Notary Association (NNA)
9350 De Soto Avenue
P.O. Box 2402
Chatsworth, CA 91313
(818) 739–4000
www.nationalnotary.org
This national association of notary professionals provides a one-day notary training seminar. The NNA seminar registration fee is $159. Participants will be able to take the examination at the end of the workshop. ”