If you are a new writer who has been offered a contract or representation by an agency you found on the internet, play it safe and make sure they are legit. Unless you are seeking self-publication, no publisher or agent should be asking you for money. A helpful resource for checking up on publishers and agents are the websites Predators and Editors and Writers Beware.
Looking for a publisher for your book? Check out the most recent edition of The Children's Writers and Illustrators Market. You can also look online at "Colossal Directory
of Children's Publishers."
FOR A CLEARINGHOUSE OF HELPFUL WRITING AND PUBLISHING SOURCES, LOG ONTO MY WEB PAGE: RESOURCES FOR CHILDREN'S WRITERS.