Where do plugins go after I install them in multisite?

Hi, I’m a WPMU newbie, please be nice :slight_smile:. I run several other wordpress sites, most are single instances, and one other multisite instance. I want to give WPMU a really good workout to see if it might provide a replacement solution for my current production site http://www.darwinholidayapartments.com. I’ve installed a whole bunch of plugins but…. how do I configure them? I can’t see anywhere on the admin menu how to access them. I feel a bit dumb about this …. hoping you can help un-dumb me! cheers, Cathryn