I used to have some great vending business bookmarks but I'm afraid I lost them all. Here's some advice:
Do <B>not</B> go with any of those "all in one" companies unless you personally know someone who used them. There are a few major assholes out there that constantly change their names and spend all their time ripping off vending newbies.
Do a <B><I>lot</I></B> of market research ahead of time. Be sure you can place the machines. Get advance commitments wherever possible.
Depending on what you are vending, expect as little as pennies per day on any given machine. Do <B>not</B> believe the inflated numbers the vending machine suppliers give you. Find message boards and ask for the real deal on whatever product you are thinking of going with.
Look for alternative products and services to vend. There are already a billion candy machines out there, but there are other, less-saturated vending niches like table-top games you can place in bars and restaraunts.
Finally, your best friend is
http://www.bbb.org/
SpaceAce