Valve Time is a Source community contributor’s best friend when it comes to advice for mod tools and tutorials.
The Team Fortress 2 Wiki is a one-stop shop for all information related to Team Fortress.
The Twitter for the official Team Fortress 2 Blog
Jerma’s official Twitter. Jerma is a Youtuber who makes Team Fortress commentaries.
STAR_’s official twitter. STAR_ is another TF2 Youtuber who generally reviews new weapons the day they come out.