I was just about to start an adwords campaign to send some traffic to a survey site, but my friend told me not to since Google doesn't like these type of sites anymore. Is this true?
I haven't heard such a thing, in fact I've seen survey adsense advertisments but you can always check inside adwords for policy change or modifications.
Guidelines and Policies are here: adwords.google.com/support/aw/bin/static.py?hl=en&page=guidelines.cs Nothing specific to surveys but if you use it to collect personal information (email), it will fall under the Phishing for Personal Information section.
Don't go there - it is one of many types of sites that will automatically get you a low quality score, even though Google have not specifically told us such. If your merchant makes money from commissions, it's probably a risk to your account to promote - ie mortgage sites, insurance sites, credit card sites - where they are promoting multiple merchants themselves.