Classified Advertising

With classified ads you can typically just use your adwords ads. (it's the same classified ad. format anyway and you have proven it to work). But you really need to mention about giving away a free report and then direct them to a squeeze page or tell them to send email to an auto responder to get their free report to get good sign ups.

For Classified Ads in Suburbian Nerswpapers 

SCAN - Suburban Classified Ads Network

Liberty Publishing

Magazines also have a classified advertising section.

You can determine the magazines to advertise in in you niche by looking at the following.

magazines.com

amazon.com

TIPS: Test your advertisements with adwords first. When you have a winner then take the same ad. offline.

Trade Associations The Forgotten Advertising Source

Trade associations offer newsletters that you might be able to advertise in. Since it is a trade association you also have the benefit of getting an implied endorsement. 

marketingsource.com/associations

weddles.com/associations

If you can't find an association for your niche just do a google search  - your_niche + association