I am bilingual, based in US. If I build a site in a language other than english, targeted to a foreign country, do I have to set up adsense for that particular country? And how can I see the ads the people from that country will see? Thanks in advance for your advice.
Yes, that's possible. Check this out, this might help you: http://www.google.com/support/forum/p/AdSense/thread?tid=661189ce1d648e7d&hl=en Good luck!
You can run on one adsense account under different sites with targetted country. You can check whether that the targeted people are visiting your site or not through google analytics.
No need. You just need to get approved by adsense and do whatever you want as long as not against any TOS