A reader asks if we can suggest any books for people "with a serious lack of grammar skills. Also, the best thesaurus and dictionary." That's a heavy responsibility--there are innumerable references to choose from, and people's needs are idiosyncratic. Here at PC World, our official guides are "The Chicago Manual of Style" ($36), which styles itself "the essential guide for writers, editors, and publishers," and "Merriam Webster's Collegiate Dictionary, Tenth Edition" ($20).

The Chicago Manual is complete and authoritative, but its index is massively unintuitive. That makes finding the information you need somewhat challenging. But if you can find it, rest assured you stand on solid ground. As copy editors, we especially appreciate the chapter "The Editorial Function." The section "Watching for errors and infelicities" contains the invaluable reminder, "It is . . . incumbent on the editor to be persistently mindful of the unique relationship between the author and his or her work."

Webster's Tenth presents no problem in navigation. With many of its definitions, the book includes helpful paragraphs on usage. Often we find exactly the guidance we're looking for. As you may gather from our tips, we don't always agree with Webster's endorsements, but the information is there and easy to find.

For synonyms, a top-notch thesaurus is "Roget's International Thesaurus" ($17), now in its fifth edition. Roget's well-organized, comprehensive groupings of words with similar meanings simplify the hunt for the right term. Subtle variations of words within categories can help clarify the elusive meaning you're chasing.