The October issue of Writer’s Digest lists several agents who deal in children’s fiction–at least one of them specifically mentions picture books. Some greeting card companies encourage you to make a basic drawing to go along with the text of humor cards if the joke requires one. They’re not likely to use your drawing (especially mine), but it can help sell the text. Your drawings might do that for you, but I’m going to assume that you’re a talented illustrator and will sell the whole package. 😉 I was interested in this field for a time and did a lot of research–there are actually quite a few who both write and illustrate, but I can’t tell you any statistics when it comes to a first-timer. If you are unable to get a copy of the magazine, I can p.m. the information to you.