I read they like it if you have the story first and then they pair you with an illustrator. But if you can draw too, it's a plus and you talk to the your publisher about that and they prefer it since they're only dealing with one person. What they don't like is if you have already choosen someone else as an illustrator, that's not you...Then if they don't like the drawings the other person did, they reject you immediatley. Have sketches ready. The first thing is to try to write it out. As long as it's in regular paper, best to use times new roman or ariel font, size 12 double spaced. Do a little research on google and there a lot of great website's with information on writing children's books. Then if you don't want to deal with a lawyer there's the whole trademark and copyright things you'll deal with, but it's pretty easy. Just write first, find an agent, tell your agent or publisher you're also an illustrator--and if they like your story and drawings your all set. I know, I'm going through the same thing, and there are classes you can even take at community colleges--just one day, during the weekend, that can help with publishing children's books. Also if they do make you sumbit pictures never send the originals--make prints of your illustrations, that way they won't be damaged.