Apache VHOST, Database error?

I’m developing several sites locally on my iMac, running OSX.5 and MAMP. Everything connects through localhost:8888, but I had several virtual hosts configured through Apache’s nifty technology.

The whole set up worked nicely for a little while, but now everything has gone haywire! Specifically, the MySQL relational database seems to be on the fritz, because I can access the pages (sometimes) and I get a database connection error. It is a WP error page, so I know that something there is still working…

UPDATE: now nothing on any of the virtual hosts is getting through. The web browser just says that it

can’t find the server “virtual-host”

(substitute ‘virtual-host’ for the specific name)

Does anyone know how to configure Apache’s virtual host system, or even better, does anyone know of a good resource for learning about Apache? (WP specific, or just general. I’m not picky)

Thanks, because I’m a little dead in the water here until I can get my local environment back on line 🙂

–MindBlender 3D