As Tim mentioned, you can click on the "Find A Pro" tab on the above banner and I also suggest "Googling" San Francisco real estate to bring up the contact information for real estate offices in the area.
Give a few brokerages a call to interview over the phone and select the agent who knows the market well and who you will feel comfortable with.
Prudential Connecticut Realty
San Francisco Property Management - The Azari Real Estate Group
View available rentals and our owner services and tenant services.
Craigslist also have rentals info ... Trulia has a rental section too.
I always like to be helpful - let me what you are looking into.
Helen Yuen, Open Home Professionals (415) 583-3535
Are looking for a someone to assist you in finding a rental in SF? If so this type of agent often does relocation and charges a fee for his/her services.
Here is someone you can contact:
If you elect to do it on your own your best bet is to search craigslist http://sfbay.craigslist.org as the majority of rentals are marketed on that site.