I am in the process of converting my 12 inch vinyl to CD. I have a turntable plugged into the sound card with normal RCA plugs, and use different software, although Nero has a sound grabbing and editing tool in there somewhere.
A cassette deck will connect through the same RCA plugs. You will need to configure the software to find the track breaks, or you can edit your own after the stream is on the HDD. Sometimes soft moments can be confused by the software for end of track.
Recorded music is compressed according to a protocal called RAA (I think I've got those initials right, better check). You need to have a deck that gives the uncompressed output, which most probably do if they have a pre-amp. However, some newer models do not have a pre-amp as it's cheaper to leave that to the main amplifier. My turntable has a switch inside for this, check your cassette deck's compatibility.
Some software tries to remove noise after getting the music tracks onto the computer. I have found it better not to use this, just live with the slight hiss, or pops/clicks on LP stuff. Removing the noise very often leaves a degraded, slightly dull, music result in my experience.
