You may have basic noise reduction capabilities in your CD Writer package (more so in full retail than OEM).
A lot of the turntables you can buy now have an option for line-level output - if you have to use a headpone out from a system with a deck, set the tone controls to central, turn off any graphic equaliser etc. If your software has decent noise reduction, turn off any provided by the equipment.
If the LP is in good condition, you might be able to skip noise reduction, but LP noise transcribed to Cd stands out like a sore thumb, as you're not expecting it!
http://www.delback.co.uk/lp-cdr.htm - one good resource on the subject