CCH specializes in tax and business law information and makes a point to make themselves available to journalists (including freelance writers and other flavors of professional writers) to help provide reliable tax information. They also publish a free guide to provide specialized tax help to journalists and photographers. More information on the guide is available on their site.
To get the guide, simply email Leslie Bonacum at mediahelp [at] cch [dot] com. This guide is printed — hard copy rather than an ebook — so you’ll need to include a mailing address of some sort. There is no charge for the guide.