Ebay has some annoying fees to go along with it. And a lot of times, being a newbie can get you less for your stuff at auction. The longer you've been around, the more you can get.
Craig's list is easy, free, and no seller's records to worry about. You can create an account if you want (easier way to keep track of your selling). And when you do post, a fake email is created, so people browsing don't see your actual email or phone number unless you put it into your post. When some one emails you, it goes directly to your inbox. From there, if you reply back, then they will see your real email address.
Do a quick search here on the Dis of "craiglist scam". A few topics have been brought up about people trying to scam you of money. The biggest one is people willing to send you above and beyond what you're asking in a wire transfer. Then they'll ask you to refund the difference after shipping charges. The wire is fake and you're left with paying the money order because you cashed it. And usually ignore the low ballers.
Always put Cash or Money Order in your post, and how you would like the item to be picked up. Such as pick up only from your home, or a meeting location halfway. I usually wait 24hrs prior to responding to any posts. I get a lot of junk responses, and it can take a while before you get some one who actually wants your item and willing to get it. Usually it's the ones that say "I'm interested in this. I'm available to pick it up at such and such time. Here's my contact information." That's when I'll reply back with pick up location and my phone number.
If you find yourself wanting to sell a lot of things on ebay, then it might be worth it in the long run. But just a few things won't get you much as you would think. Paypal also has fees with auctions. You might also want to take some of the nicer kids clothing, and try to sell them at consignment shops like "once upon a child", they take a small portion of the sale, but it's sold at a good price. Usually yard sale will net you 75% or less of retail and a consignment shop can probably get you as much as 50% (all depends on the item too).