Whether you're a student or a diplomat, finding a place to stay in Geneva is difficult. Finding a short term, affordable place to stay can be a time consuming process. For non-French speakers, the effort is doubled. If that were not enough, Geneva is currently in the middle of a horrible housing crunch. That said, there are some on-line resources that might help you out.

The first is 'Welcome Geneva Center' (Centre d'Accueil Geneve) http://www.cagi.ch/. They have an office near the Palais de Nations where you can sign up for their list of available rooms and apartments. They are friendly and usually have several English speakers on staff. They can also help with finding school, doctors, and other local resources.

The next is the World Radio Geneva Classifieds http://www.wrgfm.com/ (registration required), and English language site where people post sublets, apartments, and rooms for rent. You might also try visiting the bulletin boards at the UN offices and local universities, or posting an ad yourself. Most UN staff takes at least one month of contract break a year, so there are a lot of chances for house/apartment sitting.

Finally, there are the local papers such as Tribune de Geneve http://www.tdg.ch/accueil/petites_annonces/index.php?Page_ID=6189. Even if your French is very basic the ads are not to difficult to decipher with a dictionary and some patience.  You may want to enlist the help of Francophone friend to make the phone call.

While you are looking, or for stays of less than 6 months, there is always Studio House Acacias, http://www.studiohouse.ch/ which rents small studios by the day, week, or month. Studios start at 60 CHF/night (US$45), with a discount on longer stays.

Extended or Permanent Stays

For longer or permanent stays, start with http://www.genevecentral.ch/regies.htm which has a full list of 
Geneva's "regies"-- Swiss rental agencies. Dealing directly with these agencies, whether you are a fluent French speaker or non, can be very time consuming and frustrating. If you can afford it, it is worth hiring someone to help with the communication and paperwork. Some of the Swiss rental insurance agents can and will help you with this-- once you have purchased insurance from them of course (the rental insurance is required by law anyway).