There is a chain of bookshops called Payot. They have a shop in Geneva which they claim has the "biggest choice of English books in French-speaking Switzerland" :
Payot | Geneva English Bookstore
They also have a store in Lausanne which has a reasonable selection of English language books and you can order lots more.
You can also order from Amazon.co.uk. They knock off the VAT as the goods are technically being exported outside of the EU. Sometimes when the postman delivers the parcel he asks for an import tax, but more often than not, he just hands over the goods. I've never understood exactly how that works/at what rate they calculate the import tax/why they do not consistently charge an import tax, but I'm not going to complain, since the situation seems to be working in my favour!
the rule semms to be, anything below 200 chuffs they leave you alone, so if buying a load of things, ask Amazon to pack them in seperate lots ....
There are basically two main english book shops in Geneva. The first is Payot, as Lausannebrit wrote, the second being "Off the shelf".
The former located on the right side of Geneva (around the train station), the later on the left side of the city (near the university.)
websites:
OffTheShelf, the English bookshop in Geneva ...for English books and more!
But if you order a bunch its still easier, and cheaper to get second hand from US or UK through Amazon.
D.
There is also a library at CERN which isnt too bad. I think that they can arrange inter library loans if they havent got what you are after. If you need any help, send me a PM.
For other books, the American Library and Holy Trinity Church both do bisannual book sales (December and June). You can find books there for 2-6 francs each!