If you have a lot,it may be worth investing in some stand alone Vinyl/cassette to CD equipment. They range from about �30 to a few ton. They'll get rid of all hisses,clicks and some will even turn mono to stereo,although I can't see why anyone would want that. I get 'computer active' mag. No doubt if you checked their site you would find useful reccomendations
The USB turntable is the current choice, adequate and ease of use for sure....for something a bit more jazzy, Pioneer do a great range of hifi cd recorders with a phono input like these