Finding correct OID

[mrscary]

Can i ask a dumb, basic question? I get how to run SNMPWALK or SNMPGET to see if you can pull SNMP data, and it lists the OIDs, but if you have a new piece of gear, and no other templates work for it, you have to make new one.
THAT is kinda new for me, but I am game to try.. but how do you find out what each OID means for a specific device?

for example. I have a bunch of HP 402N printers, the SNMP Printer template, only sees the NIC, not toner, not printed pages, etc.
So, i figured, I'd try to make a new template.. but i cannot find a list of the OIDs for this printer. I did find OIDs for a Dell switch, and was able to copy a template, and alter it with the OIDs i found to show me the switch's temperature.. but Dell showed that on their page.. where do you guys find the information about the OIDs you're using to create your templates?

[bmfmancini]

I have made my fair share of templates here is my process

1.) If I am looking to collect interface stats almost always the default interface query that comes with cacti will work
2.) Decide exactly what you want to capture i.e for a firewall connection count,ipsec tunnels ,blah blah
3.) if there is an SNMP mib file available for the device then the OID's are usually listed
4.) google is my friend usually if you search Cisco CPU oid there are a ton of sites that have that info

you then need to decide if you need a data query or a graph template if you are looking for a single OID then you can make say a CPU usage Single OID data source and attach it to a graph
if you want to collect a bunch of OID's then a data query would be your best bet