I hope you're hiring competant guys, otherwise you'll be spending more to teach them/let them learn than you're charging your customers.
I've seen too many "techs" to know that most are full of sh!t. Yes, most will claim they know alot but they only really know how to install an OS and a driver or two. Anything more than that and they'll be stumped.
Easy question: How to fix a modem that is using an IRQ that is being used by the serial port?
Easy qeustion: Monitor shows out of sync when booting the machine and just about to load the desktop.
Med question: What do you do when starting Windows, you get child device errors?
Med question: What does Exception OE and OD in a BSOD mean?

Med qestion: What does "windows protection fault" mean? How do you fix it? (hint: many various ways)
Hard question: Hard drive used to work, now does not boot. You cannot format it but you can partition it although nothing changes. Physically, the drive is ok. How do you fix it? (Hint: corrupt fat or sector zero. How do you fix it?)

Hard question: What do you have to do when you install IDE drivers that made the CDROM not show up in Explorer (or anything for that matter) no more no matter if you uninstall or reinstall the driver? Hint: PCI settings in Registry.
That's it for now. Bed time.