In today’s tighter market, it is even more critical that you carefully study the guidelines and sample copy or book catalog of any publisher you plan to submit to. With many more writers out there competing with you in the marketplace, it is even more important that you study the publisher carefully and follow the guidelines for each one exactly. Never assume that your book is so special that you can send five sample chapters when they clearly asked for three. With something like a book proposal, it may mean that you need to tweak the proposal between submissions to better fit the next publisher you are going to approach.
It is also important that you keep up with the changes in the industry, especially in regards to submitting electronically. Although some publishers were slow to keep up with the changes in technology, these days most publishers have a Website and correspond with their writers and potential writers through e-mail. And even if they don’t want the initial contact to be through e-mail—some actually still want a snail mail letter—many will prefer to correspond with you by e-mail over the length of your involvement with them. I've heard some new writers swear that they don't want to get involved with the Internet, but in today's publishing culture that involvement has become mandatory.
Since most publishers now do have a Website, many of them have their guidelines available on the site, as well as a lot of information about their company and what they publish. You can learn something about their ministry or denomination, find lists of the books they have published or samples of articles from their publication. Such resources improve your chances of getting that manuscript to–the editor who can appreciate your work. It’s your job to find the right address.