The easiest material you'll ever sell is based on your life. In addition to personal essays or articles based on your life you can use the life passage that you're currently in for material.
For example, when I was a young mother, I wrote for parenting magazines, when I was running a business, I wrote for business magazines, and I've always written for writers' magazines. Along the way I've written about all the tensions and traumas of various life passages, because this kind of material is very easy to write and to sell. You've got anecdotes ready to hand: your own, and others, who are going through the same life passage.
Your life offers you a fantastic array of material because whatever your current age, you instinctively know things about your age group that no one of a different age group can know. This is great material for a freelance writer.
Let's see how this might work. Let's say that you're a stay-at-home parent. Ask yourself some questions, and write down the answers. What do you most like about staying at home with your children? What do you dislike? What's your greatest challenge? Pick one answer, and free write (write for ten minutes, without lifting your pen from the paper) about it for ten minutes.
Spend a couple of days free writing, and talking to other people who are in the same life passage. Find out what they like, dislike, and what their greatest challenges are.
You should now be bubbling with ideas for articles - perhaps you've even come up with an idea for a book. Send out some article proposals to magazines and Web sites. You can also write a few essay-length (under 600 words) articles to submit immediately