Take a look at some great Battletech content:

Battletech Podcasts:

The Mechbay : This is a great Podcast that focuses on Classic Battletech.

On the Origin of Battlemech's Podcast : This is a deep diving podcast that centers around each individual mech, its history and lore.

Renegade HPG

Battletech Wiki:

https://www.sarna.net/wiki/Main_Page

Battletech Paint specs examples:

https://camospecs.com/

Makers of Battletech: https://www.catalystgamelabs.com/battletech/

Battletech Game aids:

Flechs Sheets (electronic sheets usable on phone / tablets)

https://sheets.flechs.net/

Battletech 3D Terrain and 3D Prints and STL's:

Steel Warriors Studio:

https://steelwarriorstudios.com/collections/thunderhead-studios