A DSLR (Digital single lens reflex) is great but not necessary-
A DSLR can be restricting...
they can't easily do macro close-up photos and their bulk makes it difficult to have the camera handy at all times.
A full function point and shoot style camera is easier to carry-
Students are expected to shoot a lot for the class and having the camera handy is helpful.
Megapixel size is not important (anything 5 mp or more is OK). Style can be Digital SLR or point and shoot Digicam.
The camera MUST have manual control over the Shutter Speed and the Lens Opening.
(Shutter priority and Aperture Priority)
A good tripod is important, used tripods are reasonable and can be found at Ebay.
Lighting is extremely important for photography. A portable light is valuable when natural light or indoor light isn't best for a strong photograph.
LED bulbs are becoming inexpensive, don't get hot, are
long lasting, and very durable..
Get an LED bulb that is at least a 75 0r 100 watt equivalent.
SD cards are becoming very inexpensive. The size should be enough for at least 200 images per shoot. I recomment 8gb or larger. You should have one for your camera and also one in case you fill the first up or it is lost or damaged