AUDIO

A headset (Plantronics or Logitech or Microsoft are recommended brands and if you have the option, go for the USB plug – not essential but they tend to be more compatible and easier to install).  You can find the Plantronics or Logitech or Microsoft at Best Buy, CDW and other electronics stores.

Or a more expensive but excellent solution for audio is a speakerphone such as http://www.goelectronic.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=PHOENIX+AUDIO+DUET+PCS

What is NOT recommended is a separate microphone (such as built in to a webcam).  A separate microphone and speakers (which again are NOT recommended) as distinct from the recommended headset or speakerphone will create echo and/or feedback in the classroom.

A USB connected device is not a hard requirement – they are just simpler to hook up in some cases.

VIDEO

A webcam -- Logitech again is a recommended brand; here are some models at varying price range:

http://www.bestbuy.com/site/Webcams/cfcat/pcmcat170900050018.c?id=pcmcat170900050018

http://www.bestbuy.com/site/Logitech+-+WebCam+Pro9000/8380593.p?id=1179165373906&skuId=8380593&st=logitech%20webcam&cp=1&lp=1

http://www.cdw.com/shop/search/results.aspx?key=logitech+webcam&searchscope=All&sr=1&Find+it.x=0&Find+it.y=0

Of course you can find these and other brands at many outlets and the sites provided are some of many online order houses.