San Francisco is a delightful city that any traveller should visit at least once. Also known as the 'City by the bay', it is home to such distinguished landmarks as the Golden Gate Bridge, Coit Tower, Alcatraz, and of course those adorable cable cars.
Yet, as anyone knows, truly useful information is not a mere list of attractions, rather a guide to the things you should be aware of... so here it is:
If you decide to visit Pier 39 along with the millions of tourists, be aware that the 'clam' chowder may not actually be 'clam' chowder, and will certainly not be much like a similarly-named dish served on the East Coast.
When dispensing donations to the homeless, remember that besides the old-fashioned paper, plastic is also a viable*, if not preferred method of payment.
The public transportation system is known as 'Muni', but do not rely on it for transportation.
Although San Francisco is famous for being an eclectic, multi-cultural city, keep in mind that the inhabitants of the various districts are not automated displays, but actual people, and as such, are often irritable. Therefore, exercise caution and try not to make yourself obvious as a tourist.
Using the word Frisco is a sure indication that you're a tourist.
There you have it. Understanding the above stated guidelines, your experience of San Francisco should be a pleasant one.