I'm assuming that it isn't just new plugs in general, that there is a specific application you have in mind.
I probably would start with the electronic catalog, not necessarily because it's better, it's just more readily available. If I didn't find what I wanted to know there, I'd move to the old faithful paper catalogs.
If after checking both of the usual sources and not finding what I needed, I would either check on the manufacturer's Web site, or even better, call the tech service number and talk to a real human. I have found a call to tech service can get more information in a shorter period of time, plus it's nice to talk to a person.
-- Craig Bradley
NAPA, Lansing, Mich.
2008 Counterman Counter Professional of the Year