If you have software on your computer that will allow line-in recording, you only need a stereo cord that goes from the ear phone jack on a cassette player to the mic jack on the computer. May be other ways, but that's the way I've done it.
Hey, Chuck...I purchased (at Best Buy) a device that records from stereo cassettes, and lp's to your computer. It is made by xitel (around $80)....It has everything you need, but like Marc said, it takes a little while to do, but worth it if you have a lot of cassettes and records. Also, Floyd's records in Ville Platte had what looked like an old fashion radio/record player that actually played LP's, cassettes, and other input sources that you could then burn to a CD...all in one unit...it cost around $200.
My problem is the quality of the USB turntables.
I prefer my 35 year old Thorens TD160 with an Ortofon MD. That's also better for my LP's.
Larry has a point concerning the software, because that's maybe better.
I use Adobe Audition for the time-eating jobs.
I use a Mac with iTunes and Jukebox. I had a simple portable cassette recorder/player and plugged it into the computer with Jukebox on. I then recorded the whole thing as a Jukebox track and then edited it. When finished, I exported it to iTunes as an MP3. Sounds like a lot but it is really very simple. It is time consuming like the others said. Good luck.