Mudjack,
Some of this depends on whether you are simply trying to copy from you MD to PC, of whether you also want to edit, add effects, etc. I'm not an expert but...
If you have Windows Media Player, you can simply copy the MD to PC, then CD, with that program. It's fairly easy and Medial Player is free.
If you also want to edit, etc. you will need one of the programs mentioned above or one of several others. It also get's kind of complicated trying to edit and add effects - but makes me sound a lot better (and I can use that, as you know!)
If you want to get really serious, you can record directly to your PC, leave the MD out of it and then manipulate your stuff on the computer. I have a program called N-Tracks that enables me to do way more stuff than I can comprehend.
The other question is your sound card - often the basic ones that come in the computer are fairly limited. If you want to get good quality recording in you PC you may want to upgrade.... then a mixer, good mics, pickup in your guitar.... .... can get expensive....
L