Sweet Charity
There's a really good (despite the fact that it's the Guardian) article here , which tallks about typical attitudes to fundraisers. While I don't work on the door to door approach, I can understand a great deal of what he says about attitudes - it's funny how scared some people become when they find out that you earn a living by asking people for money.
What he doesn't add is the way this continues even in social situations. I try to gently point out to people that it's just a job, and like everyone else I switch off when I come home at the end of the day (well, at least I stop thinking about people and places as potential targets). But they still sometimes back away - people are so funny!