It's subjective. What information have you been asked to include? Is it overall health of the network or is more specific information required? For example: by device type, vendor, region/country, node-level or interface-level?
What period of time do you need to report for? Should your report include any data relating to utilisation?
Before you start, I'd suggest you decide what information you want to report on and then build a report using either the web-based reports or report-writer in NPM.
It's just an example, but I created a report some time ago in Solarwinds report-writer to show the availability of Layer 2 switches at one of our sites (based on some custom properties). This shows availability per device.
Under Select Fields tab:
Select the following fields
Field: Node_ID sort * function *
Field: Vendor_Icon sort * function *
Field: Node_Name sort ascending function *
Field IP_Address sort * function *
Field: Availability sort * function AVERAGE
Under Filter Results tab:
Select records where all of the following apply
Records where Site is equal to Head_Office
Records where Model is equal to L2_Switch
Top XX tab:
Show All Records
Time Frame tab:
Named Time Frame
Time Frame Last 12 Months
Summarization tab:
Do not Summarize the Results