SharePoint information architecture: start with the questions
Most failing SharePoint intranets share one trait: they mirror the org chart. Staff do not think in departments, they think in questions: How do I claim expenses? Where's the latest brand template?
Start with the top 20 questions
Interview a handful of staff and list the questions they ask most. Group them. These groups, not the org chart, become your hubs and navigation.
Use metadata instead of deep folders
Folders force a single path to every document. Managed metadata (document type, department, status) lets the same document appear in several views and makes search far better.
Keep the hub structure flat
A hub site per major area, a small number of sites under it, and avoid nesting beyond that. Flat structures survive reorganisations.
Measure, then adjust
Use the built-in search analytics to see what people search for and fail to find. Fix those first.
A good intranet is one where people stop asking where things are.