In this Whiteboard session form Moz, Rand goes into detail on what the different types of landing pages you can create. First there is the landing page you create (Or us) that drives an audience to it, then there is the landing page that is created just to convert your audience to do something. Then there is the landing page that does both. This video and article do a good job of explaining both and what to look for when setting up your landing page (Or instructing us what to set up).
Please check out the Whiteboard session below from Rand Fishkin, founder of Moz.