This is a manual describing an approach inspired in the Open Standards for the Practice of Conservation, called Project Management for Wildlife Conservation, created by WildTeam.
While the manual can be downloaded here, you might also want to check this site for updated versions and associated support tools and templates.
This manual was developed in response to a global assessment of capacity needs for project management in conservation project, you can read more about this and the resulting scientific article in this story featured in CCNet News.