My boyfriend and I are attending school in Florence, Italy for a semester starting in January. We're getting our airfare lined up now and want to know which airports are best for changing planes and layovers in case of weather. We live near San Francisco CA and neither of us has been farther than Northern Mexico in our travels. We both speak passable Spanish and Italian... A friend told me to always take my own market bags when I go to the grocer, Is there anything else we should watch out for in terms of culture shocks?
Any tips would be greatly appreciated....Thanks.

Start with this link !
http://www.slowtrav.com/europe/bob_tips.htm

By best airport for layovers in January, I assume you mean in the US, as European airports generally don't get snowed in. In the US, the further south you can change on the eastern seaboard the better. I would avoid Boston, New York and DC airports as snow can really affect those airports. Chicago is a possibility, as they certainly have experience with snow, but I don't have first-hand experience with changing planes in January in Chicago.

Atlanta, Dallas or Miami would be the best choices, IMO. Someplace like Phoenix would work, not sure they have non-stops from there to Europe.

As you have probably discovered, you can't fly non-stop from San Fran to Florence. However, if you can fly to Rome non-stop from San Fran, that would work fine, esp if you can then connect to a Florence flight (i.e. your bags would be automatically transferred.) If you can't get a flight into Florence from Rome, you can take the train from Rome in about 3 hours. If there is a non-stop from San Fran to Milan that would be another good choice, again try to get a connecting flight to Florence, as the train ride is longer. (Note that there are two airports in Rome and Milan, most international flights come into Rome Fiumicino airport, and most international flights to Milan go into Malpensa airport. Make sure any connecting flight to Florence departs from the same airport you are landing in, otherwise you have to take a taxi or bus to the other airport, which will add a lot of time to your journey, esp with luggage.)

I think you will learn a lot more about living in Florence form other students in your program, your professors and people you meet. Hopefully, you will be giving us tips. I have lived in Asia and now live in Europe and have generally found that the Cultures Shock! series of books published by Passport books are good and informative books on living and working in another country. There should be one for Italy, and may even be one for Florence. You can find them at amazon.com or your bookstore should be able to order one for you.

Thanks for the suggestions... I'm excited!
Only 4 months to go! : )

Check direct flights from San Francisco to other European cities like London, Paris, or Frankfurt. From any of these you could connect to Florence. Also try fares to Pisa, an hour from Florence. Pisa has an airport whcih has a trainstation, so it's easy to get to Florence.