If you want "personal experience" advice, I recommend HIGHLY the Institute of Children's Literature. If writing for children is not up your alley, don't worry, what you learn there can be used in every avenue, not to mention they have courses geared for writing for adults as well. If you are looking at taking courses, you will not find better teaching than here. I enrolled and was amazed at how much I learned that was valuable in a career as a freelance writer. Since graduating the course I have published over half a dozen articles in a woman's magazine and is also writing scripts for a radio station. Doors will open, trust me.
Aside from taking courses, are you looking for websites that you can write for? I may have misunderstood your question.