You'll want to get 3 licenses:
P&C license (Property & Casualty)
Life & Health license
Securities License (Depending on the state that you live in, this could mean a Series 6 & 63 OR Series 7)
The reason is that most auto insurance agencies now sell auto, home, life and investments. Even if you put a specialist in your office to sell the other stuff you will still need to have the licenses to get commissions on them.
I would talk to Erie Insurance. They sell as independent agents and offer more than one company. This can be very important. Lets say you own a State Farm agency and then six months from now they have a huge rate increase. You lose half your customers and can't do anything about it. Go independent and those same customers can call you up and you can rewrite them with a different company. You can order your study materials here:
http://www.dearborn.com
uuuh, look for colleges around you and ask them about classes... or look them up online and have them send you information.
Your local JC (cheapest route) PLUS combine it with a P/T or F/T job at a local Farmers Agency to have the quickest path to a seasoned auto agent. By the way I am not associated with Farmers; however, I know that they are a great source of OJT training on auto and dwelling insurance!