Check for the steps under "Creating and Editing External Website Views" on NPM Admin Guide
1. Settings -> Customize Navigation & Look -> External Websites
2. You might as well want to check Settings -> Customize Navigation & Look -> Customize Menu Bars (to understand where do you want this website in place)
3. This Menu Bars would be linked to the account that you are using to login -> Check -> Settings -> User Accounts -> Manage Accounts (just select the user that you are accessing to login , click on edit and check whats under Default Menu Bar and Views)
4. Below is the direct link to Admin guide
http://www.solarwinds.com/documentation/Orion/docs/OrionNPMAdministratorGuide.pdf
Point 2 & 3 are not that important at this stage , Work on Point 1 initially lets look into 2 & 3 later if required.
Hope it helps