Basically......I would give your tape heads a bit of a clean with some Isopropyl alcohol (Dont use it on anything rubber!)
Then, you can either apply a denoiser/de-clicker. I use a VST bundle from TC Works, which includes some nice plugs for removing hiss etc.
Make sure your levels into the digital domain are nice and hot, and then, ummm......yeah, convert to MP3.
Good luck!
Edit: I have to do some tape-CD transfers too! I swapped a crate of vinyl for doing about 8 x 60min tape-CD transfers. I scored some Led Zeppelin, Doors, Jimi Hendrix, ELP, Beatles.......awesome!