Hey..
It depends on quite many things. I hope I'll be able to explain you the most important things.
1. Where are you from? If you're from one of first fifteen countries that have joined the EU (European Union) like: Belgium, Germany, France, Italy, Luxembourg, Netherland, Danmark, Irland, Great Britain, Greece, Portugal, Spain, Finland, Austria or Sweden, than you can go to any employer. If they need someone they'll hire you and you could go with your contract to the municipality and they'll give you the Permission L (Long Term). With it you 'd be able to work for three month. After three month, you'd have to go to the municipality to prolong it. It's absolutely necessair to be announced at a municipale (you need a fixed address).
2. If you're not from one of these countries it might be more complicated. Firstly, quite obvious, you'd have to ask for work. If they're interested in you than they'll have to demand the federal office for migration for the permission. That may take them up to 5 weeks until they can give you an answer. Sometimes you'd have to pay around CHF 180.00 for the outlay. "Switzerland" wants to know whether that job could have been staffed by a native, that's why it could take that long.
It sounds more complicated than it actually is. Just go and ask at different companies. Switzerland is pretty open-minded (in cities).
some advice:
Try to work in some Call Center. They're always looking for staff (often it's a must to speak german, or at least French).
ahm, what more... check out that link:
http://www.bfm.admin.ch/index.php?id=1&L=3&S=0...
so, good luck