This article was found on the front page of the /r/PPC page on Reddit.
The author discloses 40 ways to improve conversion rates on AdWords campaigns through a variety of different methods. He addresses the basics such as geotargeting and adjustments in keywords to emphasize the high conversion keywords and minimize the low conversion ones. The author also covers the different types of extensions before briefly discussing ad scheduling and remarketing. He puts a lot of emphasis on having high quality landing pages that clearly cover what your product is as well as displays a clear process in order to purchase the products. He ends the list with some more information about keywords and finally a piece about how useful call tracking can be. There is a lot of helpful information in here for PPCers.