The MIBs

The release of the BIG-IP 4.x code series brought about some fundamental changes in the BIG-IP MIBs, so there will be two different sections: One for OID metrics prior to BIG-IP 4.0 (such as the 3.x series) and a section for OID metrics for the current BIG-IP 4.x codeset. If you are running a 4.x BIG-IP, most of the 3.x and prior OIDs will still probably work (several of the ones I've tried do at least), but it's a good idea to migrate now.

Just load that MIB file into your favorite MIB browser (mine is net-snmp) to view the various metrics available to you.

I have only put up and demonstrated a few of the metrics that I find to be the most effective for trending and troubleshooting. There are literally hundreds of different metrics with BIG-IP's MIBs, so don't be afraid to do some exploring.