Interview process?

Is there a cast (or set of casts) that walks through the hiring process relative to taking applicants through interviews, then making an offer, and negotiation?

The real questions about the hiring process I have are:

1. When do you notify #2, #3, etc.?  There are so many things that could happen to #1 at the offer, or even the accepted stage, that having a plan B makes sense.  To be professional, we need to notify #2 and #3 as soon as we know they won't get an offer - but when really is that?  Is there a guideline?

2. As you are going through the interview process, at what point do you stop looking at applicants?  I worry that I get into a mode that says "What if the next guy is a little better than the guy I have now and I miss out?"  At some point, though, I have to pull the trigger - are there recommendations about how to proceed?

I'm hoping there is a simple set of guidelines that talk about the process (rather than individual components of the process) of hiring someone: create a job description, post position, gather applicants, interview, make offer to candidate, decline remaining candidates.  

Thanks - 

Steve