Is there an established methodology/best practises for designing reporting portals?

The company where I work has a suite of products that generate data. The current reporting solution consists of various pre-configured reports. I've been tasked with, in my capacity of product manager, to document the functionality of these reports and analysing the custom report requests we receive with a view to designing a completely new reporting portal that would allow users to generate their own reports.

Is there an established methodology or resources specific to reporting (such as capturing requirements and data points) that guides on how to build the best possible experience for users who need to create reports?

The reports would likely be displayed in table format as well as an option to download it in xls/csv.