first of all you can't usually directly connect turntables to the PC's sound card line in socket , as their signal output is very low. Check if the turntable has a built in preamp. Only very few do (mostly horrible plasticky new ones made by Bush )
You will need to buy or borrow a hifi stereo amplifier with a 'Phono' input and cassette/ line Out socket. You plug the record player into the amp, and connect the amp's line out to the PC' s line in ( To do this you need to buy a connection lead: 3.5 mm jack plug to 2 RCA phono plugs. )Then go into windows' volume control and check the sound level.
You may also need to buy a connection lead: 3.5 mm jack plug to 2 RCA phono plugs.
I have done this with excellent results. Nero wave editor is the basic software to use, mine was in in Nero burning rom 5.5.5.6.
you can record the albums onto the PC, split them up into individual tracks, then save them as mp3s and make cd's. be sure to hang onto the original LPs though in case you lose the lot one day if the hard disk crashes!