Create an Intranet at work

General information for the website: Local company Intranet (Internal use only)
Kind of development: New website from scratch
Num. of web pages/modules: 10
Description of every page/module: Looking to create a page for each department, around 10 in total to include simple contents like documents and procedures.
Description of requirements/features: Create an internal Intranet with a strong main page which leads to other pages for every department.
Extra services needed: Customization, Optimization, Security
Extra notes: I have setup a sharepoint server at work to use however happy to use other platforms based on recommendation and ease of administration.