I've just posted this elsewhere in response to a question as to how to index a book. Thought it might be handy to others who don't know how. It's really very straightforward.

How long an index takes to do depends on how big the book is, and how detailed you want the index to be! Don't put any old word in - that's a dictionary then! Make sure that you only include words people might actually want to search for.

1. print off a copy, sit down with it and a highlighter.

2. go through and highlight every word or phrase you want in the index. I do this at the same time as I proofread it and check for graphical glitches. This is the tricky part, not in the physical action of it, but deciding what sort of things you want to put in the index. I always put way too much in, then go "why would anyone want to search for bunyips?" and take it all out.