First of all, you need a good casette deck with clean heads (preferably demagnetized), a good transport system that won't eat up your tape and has very low wow and flutter, and line level outputs. Failing that, you could use a walkman but be careful when using the headphone outs; the amplification stage there could easily overload your soundcard inputs.
Of course you will need a good soundcard. Soundblasters are ok, definitely better than most onboard (motherboard) sound devices and loads better than a CMI soundcard. Of course, you will need cables. For the casette deck, usually RCA stereo to 1/8" stereo cable is required while the walkman will require a 1/8" to 1/8" stereo cable - both are easily obtainable in most electronics stores, i think. The input on the soundcard/pc should always be the LINE IN, not the mic in. Set the volume control panel to Recording and select the Line In input and adjust accordingly. There can be a few occasional peaks but please don't peg the meters in the red.
For software, you will need something that can edit and clean the recorded wave file, and burn to cd if needed. Adobe Audition has all the tools necesssary for that. Audition's noise removal is among the best I've encountered; you will need that for removing hiss from the recordings. On the freeware side, you have
Audacity and
Kristal Audio Engine, Kristal is more better suited for multiple tracking. Audacity has some noise removal tools I believe.
