It is important to arrange temporary accommodations IN ADVANCE if you do not have housing. See off-campus short-term housing information at http://www.sfsu.edu/~housing/offcampus/shortterm.html
On-campus housing is available on a first-come, first-served basis. You do not have to be admitted to apply for on-campus housing. Because of the large number of applicants and limited availability of on-campus housing, interested students should apply for on-campus housing as soon as possible, preferably 3-4 months before the semester begins.
See on-campus housing options for international students at http://www.sfsu.edu/~housing/options/international.html
There are also a variety of off-campus housing options available to international students. However, the San Francisco Bay Area is located in one of the most expensive housing markets in the entire U.S., and it can be very difficult to find an affordable place to live.
The average monthly rent for studio (one room) apartments ranges from $900-$1,400; one-bedroom apartments from $1,500-$1,800; two-bedroom apartments from $1,800-$2,500; and three-bedroom apartments from $2,500-$3,000. As a result, many international students share a two or three-bedroom apartment with other students and thereby share the costs of rent, food, and utilities.
OIP does not recommend that you secure your housing or pay any deposit over the web or through Western Union before your arrival. There have been numerous instances of fraud perpetrated on international students trying to secure housing before they arrive in San Francisco. It is always best to meet the property owner/manager before you sign any contract or make any payment.
Students can find both on-campus and off-campus Housing information on SF State Housing Office's website at http://www.sfsu.edu/~housing/