How to get started with the BPMN modeler

We are looking at using a browser based modelling tool. In this respect , I did download the source
I am not sure how to get started on running it as an application.
Can anyone point me to a step by step instruction for doing this.
Sorry if this is dumb question, but I am a beginner.

Thanks
Ani

Check out our seed project. That should quickly get you started.