More Resources…...

Salesvault.com         
Got a problem? Open the vault...excellent article database!

SellingPower Magazine 
Excellent sales & managing resource. I also suggest you subscribe.
33 bucks a year in a career is a very cheap investment!

Sales & Marketing Management
Lots of resources for both salespeople and managers


Know Thy Competition
I wouldn't dwell on this, since the best TWO THINGS you can do are to focus on what you do best, and keep tabs on what local competitors are doing. However, if it's ever handy to do a little research, or to understand your competitor's industries, check out these sites:

Yellow Page Publishers Assn
Radio Advertising Bureau
Outdoor Advertising Assn of America
National Cable & Telecommunications Association
National Newspaper Association
Newspaper Association of America 
Newsletter serving the direct mail industry