Research publishing companies. Focus on their specialty and whether they publish your type of book. When researching, consider the track record of the company to see how many books they publish yearly. There are some publishers who will take submissions from first time authors and others will not. You also want to consider the size of the company because some smaller publishers will focus on one genre while a larger company may publish a range of subjects for a variety of ages.
Use the Children's Writer's and Illustrator's Market, or CWIM. It is updated annually and lists hundreds of publishers and it states the types of books they publish. It contains sections such as the "subject index" and "age index," which directs you to the section of publishers specializing in your type of book. There are other resources you can use such as the Literary Market Place, or LMP, although it is not as specialized as the CWIM. Both the CWIM and the LMP have valuable information about the book publishing industry. Check out their websites before hitting the bookstore to see which book best suits your needs.
Create a list of publishers to contact. This may be time consuming but will save you time in the long run by avoiding approaching publishers not suited for your work. You want your list to include the name, address, phone number, website, email address and contact person for submissions of the companies that publish the environmental genre and the age group you are targeting. If you compile your list several weeks or months ahead of contacting the company, ensure your contact list is still valid.
Contact the publishing companies from the list you created. Start by sending a query letter or email. It should be professionally written and include a summary of your book, your target market and a bit about why you wrote the book. It shouldn't be more than one page. Include a self-addressed stamped envelope if you use postal mail so that the company may get in touch with you should your query get turned down. Wait a few weeks before following up with a phone call or email.
Self publish. Authors are now choosing to publish their own work since the Internet has made it easier. There are websites that will help you create a store to sell your work and feature software that will help you develop your work. As in publishing companies, you will want to research the websites that are geared toward your book. The other option in self-publishing is to have it printed by a printer, design a cover for your book and find a distributor who will ship it to retailers. This can be a more costly process, but it will ensure that your book will be somewhere on the market.