I'm planning to apply for an international CO-OP work term as a programmer for January next year to finish off my Software Engineering degree (Canadian).
I am hoping to apply to a European company, as I have been to Europe once before and want to see more of it.
What should I know about the work culture in various European countries to ensure I'm prepared? Are there any countries I should avoid if I don't want to be stuck in culture shock mode the whole time?
There'll be more difference in "work culture" between any two companies than there is between any two countries, IMO.
The differences between countries tend to be in things other than work: e.g. language, food, architecture, climate, government, wealth, etc.
I'm an Australian who has worked in the United Kingdom (not quite Europe but close enough) for 2 x two year stints over the past decade. As a generalisation there is a difference in work cultures between these two countries. The British companies tend to be more formal and place much more emphasis on chain of command. There was a difference between the four companies I've worked for but the generalisation holds true.
I believe that cultures will vary between the various EU countries but peoples perceptions will vary dependent upon their background.
The best advice is to get over there and 'just do it'. If you've got a legitimate work visa and don't like the workplace or country it's easy to pack up and move elsewhere. The culture shock is real but that's what makes it such a fantastic experience.
Having made a reverse transition I can tell you generally (without knowing the specific country or company) that different countries have different cultures when it comes to observing the hierarchy and potentially disagreeing with your direct supervisor.
Even though this differs between companies and individuals, in some countries you get more rights as a "novice" or a "temporary worker" and can question things that seem incorrect or inefficient, while in other countries you are a "guest" and must be very careful not to offend anyone.
My recommendation is to find a few graduate students from the country you are looking to work in and ask them, since many of them worked in those countries and then worked in the US and can tell you what the differences are in that sense.
Not being stuck in culture shock mode depends more on your mind than on which country you plan to visit.
As a french having worked with people from several countries (mostly european but not only), I always felt cultural differences between us. I don't remember of any negative experience about it.
Moreover, differences in work cultures are also found between companies and even between teams in a single company. Think of the cultural differences between waterfall and agile software development methodologies.
And don't forget international companies or agencies where hierarchy and coworkers may be from all over Europe; don't forget research labs where people from all over the world may be present.
Welcome in Europe!