Specifically on Torque equilibrium and circular acceleration?
When I’m trying to remember a formula or calculate something I use WolframAlpha. When I’m trying to remember a concept I use Wikipedia
Can’t think of a physics-specific site offhand. Perhaps if you search for “rotational equilibrium” or “angular acceleration”?
I always use Hyperphysics. At school it taught me as much as my teacher, and that is no reflection on him.