Lots of great tips below, here's mine:
Your title is the first thing that will capture their attention, & after that, price & whether you have pictures.
Do a search on Craigslist for the same or similar item, & see what other people are posting it for. Also, get a feel for how many other listings there are, & how old they are (or if they have been repeatedly posted for the last month, indicating that they aren't selling well).
Your title should get attention - "Hasbro Weebles - complete set, great condition!" is going to make someone look further than "Kids toys, gently used".
Also, make sure you are posting in the right area. There is "Baby & Kids" "General" & "Toys & Games"
You can't post more than once (Craigslist will recognize duplicates & prevent it), but you can post in one category, & put up a different post in the other categories with the web link to your original ad.
Craigslist is hit or miss... I have posted some items for over a month with no response, & then a while later posted again just to see & had 3 calls in one day, with a sale. It all depends on whether someone is looking for & wants what you have.
Hope that helps. If you decide not to do CL to sell the weebles, you might be able to hold onto them a bit longer & have a spring-weather garage sale - kids stuff sells great if its clean, in good condition, & not outrageously priced! T. =-)