Just a gathering of things I've run into over time
From Xavier, this one and this one.
From a place called TDA Training, which I hadn't seen before
From Blue Sheepdog, which I also hadn't seen before
Similar from PoliceOne, with more links
Something from James
Managing Contacts(pdf document)
And if you've got a good one, let me know in comments and I'll add it, and put this on the sidebar
Added: from Tam, a good way to put it:
Not that there's anything wrong with hardware per se, but it's good to have some software upgrades, too. You know, so you have the correct drivers installed.