Make a PHP site send SNMP information to a network management app

Question

I'm trying to make a PHP website send information through SNMP. I've been reading allot about SNMP, but I'm still a bit clueless about where to start.

I believe I need to create an MIB with all the OIDs my website will use to send the info. Is this correct? How and where can I define those variables (OIDs)? Can someone point me in the right direction?

I'm using FreeBSD on the server.

Thanks in advance.