The first half of this instructional video shows a finished project of an Arduino with 4 shift registers (74HC595) used to control and 8x8 RGB LED Matrix. There is also a DS18B20 temperature sensor used to display the temperature on the 8x8 matrix.
The second half of the video shows all the code used to drive the Arduino.
Hope you have a chance to build one!
Step 1: Connection Diagram
This is the diagram I followed to setup my 8x8 with 4 shift registers.
I did NOT use the transistors shown in the top. They are not needed for this application but could be useful to scale up and add more 8x8s The transistors take the load off the Arduino but are not needed for this implementation.