From a turntable (with no amplifier) I use a Preamp. You can get one from Radio Shack for less than $20.00. I plug the turntable's two input cords (red and white) in to the back of my preamp, then use two input cords from the preamp that plug into an adapter plug, which reduces into one plug which I plug into the back of my computer (microphone jack).
I am a novice but I intend to educate myself (trial and error) to also transfer my extensive LP collection to CD's. I wish you good success!