Understand the environment you'll be in. Rehearsals will be inside in low light. This means you will want large lens filter diameter and large imaging chip. The alternative is small of each and grainy video that cannot be fixed in editing.
Audio is recorded by mics. The camcorder's built-in mics travel with the camcorder. If the camcorder moves, the audio pick-up moves. You actually have a choice. One is to have external mics. This assumes the camcorder has audio input connectivity. Consumer camcorders that have a mic jack use a 1/8" (3.5mm) connection. Consumer mics usually have a cable that is not shielded. This can pick up interference. Pro-grade camcorders generally use XLR connectors. If you end up with a camcorder that has only the 1/8" connector, you can add a XLR adapter (juicedLink or BeachTek). Generally, this is not the recommended way to go... better to have a separate recording device (if for anything else, redundancy in the audio capture and the camcorder's audio can be used to synch when editing).
There are lots of digital audio recorders out there. Zoom, Fostex, Marantz, Roland, and many others make them. If you need to be portable, I like the Zoom H4. Some have decent built-in mics - all can add mics.
Suggested shopping list:
High capacity rechargeable battery from Sony
Audio Technica AT-8022 stereo mic
Audio Technica AT-897 shotgun mic
Davis & Sanford tripod
Steadicam vest system (A Merlin should work, else the Pilot)
Sennheiser G3 wireless lav (for one-on-one interviews)
BeyerDynamic handheld (usually wired - can be wireless if you get the wireless module from Sennheiser)
Camera mount video light (LitePanel + high capacity rechargeable battery)
Learn to use the manual audio gain control on the camcorder and the digital recorder. Learn to use the white balance and neutral density filters. Learn the characteristics of the mics so the right one is used for the right reason. The miniDV tape based camcorder assumes the computer used for editing has a working firewire port because that is the only way the digital video on the digital tape will get into the computer.
The above are *minimum* requirements. The quality of the captured video will depend on you and your knowledge of the equipment and its proper use. The camcorder is only a small piece of a larger system.