During private beta, is it preferable for a person posting a question to delay on "accepting" an answer in order to encourage additional responses possibly from other schools, viewpoints, etc. that could end up being valuable to others? Or is it better to promptly "accept" when a clear and useful answer is received? I'm not sure of the balance of possibly getting additional content vs. possibly discouraging those putting lots of efforts into answering and not getting feedback on their answers. Thanks for the guidance.
My guiding principle during private beta is this: if you receive an answer to your question, and think that it is basically impossible that anybody could provide a better answer, go ahead and accept it. On the other hand, if you think that it's still possible that you could get a better answer later (from another viewpoint or drawing on a different source or something), do not accept an answer yet.
For example, yuttadhammo's answer to Where is the Buddha originally quoted as saying "On heaven and earth, I alone am honored"? contains exactly the information I was looking for, and I cannot really conceive of a better answer to this question. Thus, I accepted his answer. My other questions have also received good answers, but I think that it is possible that someone could post an even better answer to them, so I have not accepted answers on those questions yet.
As time goes on and we move through the public beta, I will probably be somewhat quicker to accept answers, though even then, I will only do so if I am fully satisfied with one of the answers I have received.
This is just my opinion, of course, and everybody is free to follow their own principles in accepting answers.
...possibly discouraging those putting lots of efforts into answering and not getting feedback on their answers.
We certainly want to make sure we're encouraging people who are producing good answers. Luckily, there's a way to do that - use your votes! You get 30-40 votes a day, and it's not like holding onto them is going to make you any richer. You may as well spend your upvotes on interesting questions and (especially) well-written answers.