How in the world do you get the MCP23S17 to work with the Arduino?

I have spent countless days trying to get this thing to work. For anyone that has gotten it to work, what libraries are you using? I found two MCP23S1.h libraries. One is by dreamcat4 and the other by Cort Buffington. The dreamcat4 one is old and requires an outdated Spi.h library which cannot be found on the internet. Mr. Buffington's is newer, but just flat out does not work for me. There is literally nothing on the internet on how to get these dang things to work. All I want to do...

How in the world do you get the MCP23S17 to work with the Arduino?