Here is what I usually send to agencies when they sign on:
Welcome to CSRnation. Now your agency can compete with the national agencies using this website. If you hit on the tab at the top of the page "Cover Depos" a map will appear. There are freelance reporters behind those red dots all over the country. If you need a reporter in, say, Reno, Nevada, just hit on that red dot, first join the group (can't send a message unless you join the group first) and then a tab will appear "Send message to the group."
You simply hit on that tab and then send your job offer to the group, please include contact info (everyone forgets that part). An email blast will go out to everyone in that group of your job. We are helping agencies get jobs covered in literally minutes. Think of the time and money you can save using this valuable service.
You just need to go to the LA group and post your job offer there. There is, however, a $49.95 yearly fee for the LA group.