There is much more to building a trail than moving rocks and dirt.
Trails are usually part of larger systems that are the result of careful and diligent planning and collaboration among user groups, land managers and funders. Trail systems often need to serve the needs of multiple user groups and must always take environmental and geographical factors into account.
While land managers and other administrators are ultimately responsible for the planning processes, committed trail users and community groups have important roles to play as well. Planning, after all, is ultimately about the big picture, and that picture includes not only the forest and the trees, but the entire trails community.
IMBA's online resources on trail building emphasize the importance of well-planned trail systems, and offer advice for how to create a trail system plan that can create good experiences for diverse visitors, minimize user conflict and environmental damage, and hold up in the future.
IMBA's books offer our most comprehensive treatments for trail building and many other important topics. Consider picking up copies of Trail Solutions: IMBA's Guide to Building Sweet Singletrack and Managing Mountain Biking: IMBA's Guide to Providing Sweet Riding at IMBA's online store.