Hi,
As a non-German speaker/reader, I feel your pain. Unfortunately, you just have to be really persistent. Although many sites allow you to search in English, the vast majority of the descriptions are in German only. This is such an obvious problem that my beginner's German class devoted a lesson to reading apartment ads. I included some of the things we learned: words, descriptions and, most importantly, abbreviations. Sorry if some are obvious, I was trying to be thorough.
Keep in mind, nearly everyone in Zürich speaks good English. If you call, remember to say "Grüezi" or "Guten Tag," followed by a very polite "Sprechen Sie English?" and people will generally be very helpful. If you email, you can just explain your situation and apologize for not writing German.
A previous post listed alot of choices for searching, but if you're going to look for shared housing, maybe focus on these sites, which are geared for students/share rentals. They are posted by individuals and most use email contacts.
http://www.marktplatz.unizh.ch/index.cgi www.wgzimmer.ch (searchable in English)
www.students.ch (click on Wohnen, enter your max. preis(rent), PLZ = 80xx, click suche)
Rooms: not the same as the US, I haven't been able to figure out what a "room" really means (it's not an actual room). Generally you should go by square meters (m2 or qm). Keep in mind that 10 m2 is about a 10 x 10 foot room (small bedroom or roomy prison cell).
Angebote: offered or available (as opposed to Gesuche, or searching)
Wohnung, whg = room
Bad, bader = bath, baths
Küche = kitchen
Schlafzimmer = bedroom
Wohnzimmer, WZ = living room
Balkon, Garten, Dachterässe = balcony, garden, roof deck
möblierte = furnished
neu renovierte = newly renovated
gross (grosser, grossem) = large
klein = small
hell, helle = bright
offen, offene = open
ruhig, ruhige = quiet
schön, schöne = pretty
zentral = central, can also mean noisy
Kuhlshrank = refridgerator
Rauchen = smoking
parkplatz = parking space
ÖV = public transport
WC = water closet (half bath)
WG = shared apartment
EG = ground floor (1st floor)
OB = any floor above ground (2nd floor in US = 1st floor here!)
HB = hauptbanhof (main train station)
Beware of Büroarbeitsplatz or variations (they're office spaces) or ads that say (depending on your gender) nür Weiblich (women only) or nür Manner (men only). Also, Kochnische means "cooking corner", usually a hot plate and mini fridge. Sometimes Studios have no bath or kitchen, so make sure there is a Bad mit Dusche und WC (bath with shower and toilet). The dates available may be "ab" (from) "bis" (to) or may say only the starting date followed by a number of Woche (weeks) or Monat/Mt (months).
Kreis = district or part of town (really means "circle'). I don't know where your work is, but for parts of town that are fun, young, lots of night life, go for zip codes 8001 (City, very expensive), 8003, 8004, 8005 (these are "a little dirty but close to places to go out" says a Swiss student), 8006 (nice, quieter, still close). The Kreis system corresponds to the last number of the zip code until you get to Kreis 9. If you really want to live in a fun/noisy part of town, Niederdorf is a good choice (Kreis 1/8001).
www.homegate.ch is also good but is best if you want your own apartment. This may not be an option for you, as most landlords/rental agencies will want you to sign a year lease, have a large amount of money for deposit, and may not rent to a foreigner. (I know, I winced at this, but remember that in the U.S., you need a credit report, which you can't get as a foreigner). If you know any Swiss who can act as personal references, that would help tremendously. Also, you will need proof of your ability to pay the rent, either in the form of cash or a document stating your salary.
Okay, I'm sure there's more, but hopefully this will get you started. Good luck!
Cheers