I'm going to be moving about 7-10 websites (5-8 with Databases - MySQL) onto our new Virtual Private Server. I'm curious what the best way to host many sites on a single server is though. Do I create a directory for each site immediately within my root directory, and then point the domain names for each site to http://123.123.123.123/siteDirectory - or is there a more appropriate way to do this?

I'm very interested in maintining control over how many concurent connections each site can have at any given time - would I be able to do that on the directory-level, or am I required to limit the concurrent-connections to the VPS itself?