If you are looking for a cheaper, smaller alternative to the "Chicago Manual of Style" you can do a lot worse than this one. I keep it near my computer. ( )

A decent enough reference guide to formal writing. Less expensive then some official writing manuals, this book is usually accurate and can provide a great first look into professional writing. The more expensive guides however do come in handy when dealing with some of the really in-depth aspects of professional writing. ( )

This book has been my constant companion for 'formal' writing ever since I took 'bonehead' English in college. ( )

A fruitful style-guide. Easy to use and lucid. ( )