I, too, knew (know) very little about what is needed but recently, I've been playing with a guitar player who has provided me some guidence. Basically, we use a mixer, two PA speakers and some mics and we're good to go. All of the players (bass, guitar, sax, drums, keys, etc..) can plug into the mixer where we tweak the effects to get the sound we want. The mixer we use is a Yamaha EX2000 but there are plenty to choose from. Ours has phantom power which is great for condenser mics when doing recording. Oh, and we can record live music directly off the mixer so there's virtually no crowd noise (unless the crowd is loud enough to be picked up by the mics).
All this said, PA systems get pricey quickly so do your research! Here's are some "kits" I started looking at:
http://www.musiciansfriend.com/live/navigation/live-sound-packaged-systems?N=100001+304603
Some of the "portable" kits look good but may not sound that great when pushed. For a mic, I'd use a Shure 57 or 58 - I actually prefer the sound of the 58 but again, I have VERY little experience with live sound.
All this said, PA systems get pricey quickly so do your research! Here's are some "kits" I started looking at:
http://www.musiciansfriend.com/live/navigation/live-sound-packaged-systems?N=100001+304603
Some of the "portable" kits look good but may not sound that great when pushed. For a mic, I'd use a Shure 57 or 58 - I actually prefer the sound of the 58 but again, I have VERY little experience with live sound.