There are many features of Grafana that can be found in the documentation, however looking at existing dashboards is advised.
Grafana comes with a login system, this means that anyone can view Grafana without changing anything. If you want to make a change, simply create an account. The login does not require activation, so you can start making changes right away, you can also login via Github credentials.
The Grafana interface allows you to save dashboards. These dashboards are stored in RDS using Postgres, this means when Grafana restarts, all you changes are still present.
All options for Grafana are stored in the grafana.ini.
Upload the RDS security group template
Upload the RDS template, use the RDSSecurityGroup resource you just created
Upload the main template, use the RDSComponentSecurityGroup resource you just created. You will be asked for a grafana.ini URL, this is required as you will need to put your RDS Postgres details into a config file.
There is a sample config file in this repo, so you can either fork this repo or create a private gist/place in S3 to use with wget. This will overwrite the default config file provided by Grafana, there are a lot of config options for Grafana, see the docs for details