Resource Guide to Wraparound
Lots of useful info here from very basic introductory to detailed implementation materials.
National Wraparound Initiative
This includes useful webinar trainings
Vroon Vandenberg LLP
Aconsulting group that does alot of work with state and other large systems to develop and support wraparound services - there site has alot of useful information on the model.
Promising Practices in Wraparound for Children with Serious Emotional Distrubances and Their Families
An executive summary of a longer SAMHSA-sponsored report, which does a nice job summarizing the model