Donald gave you some good tips. Public places where some type of event is going on is a good place to take people shots. I also recommend a powerful zoom lens. The distance between you and the subject gives both some comfort in that they don't really know you can see up their nostrils. Of course you have the steady hands problem but fast film may help with that.

In the case of shot number 1, just tell them what you are doing and ask if they mind. People involved in an event generally don't care, they figure it is part of the show.

This shot, for instance was taken at a civil war renactment. The people there are dressed in costume and expect people to be gawking at them. Also, the people that attend the event are aware of a camera but not so intimidated by it.

Good luck and have fun.