Hodgdon: http://www.hodgdonreloading.com/data/rifle

Nosler: https://load-data.nosler.com/load-data/308-winchester/

I also like the Hodgdon Handloading Annual (printed magazine format).

As far as technique - Handloader Magazine (and decades of back issues) covers the tricks and techniques for eeeking out accuracy.

https://www.wolfeoutdoorsports.com/b...loader-issues/

You can poke through the indexes and find goodies like Ken Water's Pet Loads by caliber or articles on technique.