We are planning updates to the User Manual, installation user experience and the Project Manager as well.
I believe that the changes to the User Manual will be published in the Service Pack following Q1 of our ASP.NET AJAX controls. Work is being done on the Dev Manual.
As far as installation goes - nothing has really changed from 3.5 sp1 to3.6. Simply follow the user manual. you can take a look at our "Troubleshooting" section, where most common problems are explained. Besides, there is a KB article
regarding the Sitefinity upgrade process to 3.6
If you need assistance or are facing problems installing or deploying Sitefinity, please feel free to contact us.
the Telerik team