If you are new to Joomla please take the time to familiarise yourself with the Getting Started articles.
The Build.R template is a master template builder built on Zen Grid Framework v5. Build.R makes it possible to create a wide range of website designs using the built in tools and an advanced child theming system.
If you are using atemplate built using Zen Grid Framework v4 you can find the documentation for the specific template on their own documentation mini site.
If you are using a template released after January 2013 or one of the themes that have been updated to work with T3 please also read the Using T3 articles.
Our flagship multi-purpose Joomla module has it's own mini site where you can also find information on implementing it's various layouts.
Zenkit also has it's own mini site which not only holds the demos for our standalone K2 Joomla templates but also information on using them.