Best way to digitize LP's

Looking for advice - I have a big LP library, several turntables and just as big CD library which i have already transferred to Roon and ....iTune... :) i am looking for an efficient and not too complicated way to digitize my LP's - I assume there should be a piece of hardware (with software) that i will need to inset between the Phono stage and a PC (no mac)? My turntables don't have built in Phono stages or a way to do it (i know there are some turntables that have this capability built in).

Thanks for the help!