First, if you will be living in Geneva you will need French not German. But there are plenty of expats there and plenty of English websites.
Is it cheaper? Well, my sister-in-law lives near Brisbane and she still uses dial-up because having ADSL is still too expensive where she is at. Ok, more expensive then it would be in Switzerland.
The service you will end up choosing might depend on how long you plan to stay in Switzerland. Unless you are planning on going the dial-up route, where you pay every time you connect to the internet, you will be required to sign a one year contract. I'm not sure what other providers offer, but Sunrise will give you a free ADSL modem with your subscribtion and for only a few Swiss francs more offer you a wireless modem so if your laptop has wireless capabilities you can move around the house with it instead of having to be plugged directly into the modem.
With Sunrise, their basic unlimited internet service costs 49 francs a month. Their website is unfortunately not in english but they do have english speaking people when you call customer service.
Without getting too technical you only have to decide between two basic services: 1) dial-up - where you connect to the internet only when you need to. The downfall is that during this time you cannot receive incoming calls as your main line is being used by the modem to connect to your internet service. Dial-up service is good for people that only use the internet occasionally to check their emails. For this service you pay per connection and according to the time you are online or you pay a flat rate for a certain amount of downloaded information. 2) ADSL - this service gives you a separate phone line without the additional cost of installing a second line. It is not a second line which you can use as a landline but rather a dedicated line for your internet modem. That means that you can be online 24/7 and people can still call your regular line to reach you. For this service you pay a flat monthly rate.
So, if you plan to use the internet a lot choose ADSL.