Your local dashboard project instance is located under: /var/www/html/dashboard/. Look for a file called local.config. Within this config file you can customize a few things of RPi Dashboard (e.g. thresholds, password).

See the notes in README.md for instructions.

Explanation of CPU Loads in Linux at http://blog.scoutapp.com/articles/2009/07/31/understanding-load-averages (recommended article)
In case of Raspberry Pi a value of about 3~4 is critical, i.e. all kernel cores are busy.