The 'functional schematic' indicates the PIC pins to which that I/O appears to be connected. So for example RB7 (next to an LED) indicates an LED/Relay Output. It would be a simple matter of doing a test program to verify that is correct and make the Relay tick...

TRISB.7=0
Loop:
High PortB.7
Pause 1000
Low PortB.7
Pause 1000
Goto Loop

Looks like a useful board (which they've left pretty much for you to figure), but shame they spoilt it by a silly Output Relay Contact arrangement.