The Thousand-Yard Conspiracy
Please read these lengthy pieces from Chris Bryne's The Anarchangel on the theory and practice of developing tools and skills for long-distance shooting:
Roadmap for the Thousand-Yard Conspiracy Posts
Wny Not .30-'06?
Part 1: Paper and Parts
Part 2: .300 WinMag vs. .300 WSM
Part 3: Going Long, For Short
While Chris assembles more posts on the topic, you may want to read these links and this reference work as well.