Best place to advertise room rentals in a single family home?

[Bruce P.]

Other than Craigslist (which I've heard can yield some not-so-serious leads), what is a good website to advertise single room rentals in your single family home (think house hacking)? I looked at Zillow Rental Manager, but that seems geared towards apartments/renting whole houses. Same with Padmapper (although I found some airbnb rooms  on there).  If it helps, this is for a place in the southern california area.