As well as the software, you need a sound card in your PC with a line-in socket and, preferably, a line-out socket on your record player or hi-fi. If you have those, just connect them to each other with a cable with the appropriate plugs.
If you don't have line-out, you can use the output from a headphone socket, but it's output will be affected by the record player or hi-fi's volume control.
For example if you currently have it running through your amp you could take the line out of your amp into the line in on your sound card thus using your amp as the pre amp. If you where planning on just pluging your record deck straight in then I would say yes get a preamp otherwise you'll get a pretty low level signal to record from.