Can anyone point me to a good tutorial on these and how to use them? i am stumped.
This is the obvious sort of thing to check with google, and then start reading.
From that link... A really good tutorial on Op-Amps and ADC's one of the best I've seen since I started learning electronics.
Tutorial - Experiment 8 - Digital To Analog Conversion Well worth reading from the start.
There is the ABC Thing created here at :http://www.pighixxx.com/abc-english-version/ This one is also a great tutorial Especially for the Arduino..