Each MAX7219 is like 8 shift registers that are individually addressable.
So what you is select a chip, send the regiter, send the data. It then updates the outputs to match.
Now, you can have 5 chip selects, one for each MAX7219 and select each one to update as something changes.
Or you can daisy chain them, with just 1 chip select. When you want to change a register in the first chip in the line, you do as I said above.
When you want to change a register in the 4th chip, you send the address/data, and then 6 NOP (No operation) bytes (all 0) to make the first 3 chips pass the data along.
taydaelectronics.com has good prices on MAX7219 ($1.25) and caps & resistors needed.