I've been a self-employed cabling guy for about a decade and have never gotten into installing phone systems like Avaya or NEC or Nortel. A buddy of mine has been doing so (Panasonic) and makes multiple times what I do. I'd like to make that change this year. What's the best avenue for getting certified to sell some basic (read "smaller") business systems? I don't know if I care to jet off across the country to spend a few thousand bucks for an 8 week training course, though. Is there a less intensive approach that any vendors offer?