PIC TO PIC's (data interchange)

Ladies & gentlemen;

I want a PIC to control 4 other PICs. (...USB PIC to control stepper 4 motors) (18F4550 & 4 16F628A's)
Could someone give me a couple of code lines to read/write data between PIC's ?

My Questions:
Q1 Hardware connection:
a.- Each 'slave' PIC: connected directly to 'master' (example slave1 to master.pin1, slave2 to master.pin2, slave3 to master.pin3, etc...)
b.- Each 'slave' PIC: connected as chain/network (master to slave1 to slave2 to slave3, etc...)

Q2- IF Q1 option B, I guess it's needed to Identify each pic..? how?
Q3- Wich command? (Serin/Serin2/HSerin/HSerin2/I2CRead/ \out\write) interrupts or ASM ?
Q4- Can I just send from master or I can also request data to slave??
Q5- Is there a book or website where to get that info, so I could help someone, not just ask... well that's it.

Thank you

Maybe this one may help.
http://www.picbasic.co.uk/forum/showthread.php?t=1192