The two best resources I've found that compare Byte Stuffing (also known as character stuffing) and bit stuffing are the following:
A slideshow presentation Synchronous vs Asynchronous transmissions, Bit stuffing vs Byte stuffing, framing synchronizations and how to identify them:
http://web.cs.wpi.edu/~rek/Undergrad_Nets/B06/BitByteStuff.pdf
A helpful video clip that looks at the differences between Bit stuffing and Byte stuffing:
