Here's a great summary of how to build a winning landing page:
You’re about to launch a big online marketing campaign complete with media buys, search engine placement, banner ads and blog buzz. You’ve tested your creative and your clickthrough rate is strong. You know once you go live, tons of targeted traffic will be hitting your site. Time to sit back and relax, right? Not quite yet.
Read full article: 11 Ways to Improve Landing Pages