The ultimate references for using the Macintosh for graphics and interaction are various volumes of Inside Macintosh. The most important ones for our work in computer graphics are the three below. The links below are directly to HTML versions on the Apple site. Note that the fully linked index is a separate button at the bottom of the first page you get to at Apple for any IM volume.
This first volume is quite readable and gives you a good overview.
The following two volumes are quite detailed, so you use them more as a reference than a textbook to be read. Toolbox Essentials covers, among other things, the basic event loop that you should use for interactions and for timed activities for animation. The basic principle is that you need to release the CPU from time to time in an orderly way to allow other processes to run.
This volume tells you all about drawing lines, shapes (borders and fills), and text, including basic colors and extended colors.
The entire Inside Macintosh collection at the Apple site can be accessed here.