I am always telling my HelpingYouGetPublished.com book authors that it is in their best interest to build publication credentials by publishing articles and short stories. A track record of such publications alerts agents and publishers that you are a committed writer with a professional attitude. This will incline them to take your query seriously.
Most aspiring book authors are aware of the possibility of publishing in trade, consumer, and literary magazines and journals. But they often overlook the potential of publication in anthologies. If you target an anthology precisely, and your subject or story is a good match with the editor's requirements, then you have strong odds of having your work accepted.
The monetary pay for publishing in an anthology is usually modest. The real pay-off is the credential that you can add to your CV and the complimentary copy(ies) of the anthology that you will receive. Most anthologies are handsomely produced and make attractive additions to your home library. Best of all, seeing your name and work included in such publications boosts your confidence as a writer and book author.
I do not know of any handy guide to anthology publishers, but you can get started finding the right ones for you by following the advice given on this page: http://www.ehow.com/how_6368989_published-anthology-book.html. For a related article about getting published in the Chicken Soup series, go to http://www.helpingyougetpublished.com/2004-1.html.