Leaning on local schools sounds like a great idea. My sister teaches four and five year olds (I know she's a saint, right?), and she is constantly getting requests from parents to babysit. Many of those parents also refer her to other parents with kids.

I would also consult your neighbors who have small kids, and ask them for a few reliable suggestions.

Lastly, ask for references from a babysitter ... you can never be too sure!

Do you know anyone who is a high school teacher? I found one of the best babysitters I've ever had for my daughter this way.

I've gotten babysitting jobs on craigslist before...but with anything, interview AND check references. You can write an ad for exactly what you want in a babysitter.

I would add to ask your pediatrician, if you have one in town. Friends and family are always best. Are there any relatives in the area? Perhaps asking co-workers who have young children as well if they would share their contacts.

If you have neighbors with kids, perhaps you want to ask for a referral. You also might want to try your local college/university, especially the education department.

There's a few ways you can find someone reliable. Try asking local daycare centers for recommendations, or even local places of worship (churches, synagogues). Those are people who are plugged into the community, and it's much more reliable and easier than putting up an ad someplace. Just make sure you get references and call on those references!