I have put a ton of effort into marking up my help pages with HTML id tags. Here’s an example:
<h2 id="installation_problems">Installation Problems: </h2>
Why do this?
So when people ask questions I have seen dozens times before about an issue they are having installing Zen Cart Discount Preview, I send people directly to the portion of the Discount Preview documentation which describes installation problems: you can send them the link
Over time, as you build up your list of tags that you can use in answering questions, you are enabled to not only provide better service (since you can answer more quickly), but also to save time, since you don’t have to explain the answer again and again. And on top of that, you’ll probably spend time refining the one answer you have written down to the question so that it improves in quality over time.