Are Four 74HC595 Sift-registers in a row too many?

Other Hardware LEDs and Multiplexing
13

ok, one question regarding your code:

At the moment I have it like this:

Datapin (Arduino: 11) -> goes to SI (14) pin of the 74HC595
Clockpin (Arduino: 12) -> goes to SCK (11) pin of the 74HC595
Latchpin (Arduino: 8 ) -> goes to RCK (12) pin of the 74HC595

NOW, it says in your code in the comments that "SCK goes to RCK pin, MOSI goes to Serial Data pin" what does this exactly mean? I mean, which arduino pin do I connect with which of the registers pins?

Thanks!