Tea is a core part of British culture. It is almost impossible to visit a household in the UK without being offered a cup of tea, and very impolite to decline one. There are in fact two schools of tea-drinking - the strong cuppa brigade, and the tea aesthetes, or teasthetes. These are best delineated by a splendid vignette (which I am reconstructing from memory) in the otherwise forgettable film 'Mona Lisa', in which Bob Hoskins, playing a rough cockney, is seated in a plush West End hotel. A waiter approaches:
'Would sir care for something to drink?'
'I'll 'ave a cuppa tea'
'Earl Grey or Lapsang Souchong?'
'Nah mate, TEA!'
George Orwell explains the 'nice cuppa' better than anyone, while Douglas Adams explains the allure of Earl Grey (note that they differ on the crucial question of milk first or second - I'm with George on this one).
In America, if you are offered tea, what you will get is a cold, sweet drink made from teabags, cooled with ice and with sugar and lemon added. Getting an English-style cup of tea is quite difficult. Most restaurants will provide a teabag and lukewarm water on demand, which doesn't really work. In this part of California green tea is widely available, and this is generally supposed to be made with water that is off the boil. The ubiquity of coffee shops extends some hope, but Starbucks make poor tea, selling a range of teabags called 'Tazo' that trigger the 'Nah mate, TEA!' response in me, which is odd as I generally incline to the teasthete end of the spectrum. However, most supermarkets will sell you Twinings teabags, or even Tetley ones, for you to brew in the privacy of your own home. Trader Joes have a reasonably priced own-brand range.
The real answer for the teasthete is Peets Coffee and Tea who sell wonderful leaf tea at reasonable prices. There are several branches in the Bay area, and if you can't find one they'll deliver it.
Making your own is made more difficult by the problem of obtaining a decent electric kettle, as the US's 110 volt system means boiling water takes about twice as long as with the Uk's robust 240 volts, so boiling the kettle on the stove top may be quicker.