There is nothing more valuable than when others take the time to post to your blog. Honor that investment by responding with a thorough answer when it happens. A question from an outsider, coupled with a valuable answer is exactly the kind of magnet for people looking for an answer to a similar question in the future.

I've often gone searching for an answer in Google only to be pointed to someone's blog where the answer was thoroughly answered. For example, if I search for "how to create a table in Microsoft Word" in Google, one of the results (with a PageRank of 4 by the way) on the first page told me exactly how to do it.

If there is a spelling mistake or grammatical error in the question, consider fixing that also. Good spelling and grammar are more likely to be used to search later than exact misspellings.

1. Answer questions promptly, thoroughly and accurately.
2. Fix any spelling or grammatical errors in the question (if your blog provider lets you do that).
3. Use a graphic to illustrate the answer if it helps.
4. Spell out any provisos, like "this solution works for Microsoft Word for Windows 2003" (in case it might not work on other versions). That will at least help the reader understand why your solution might not work everywhere.