Software

• Get a recording program such as Garage Band or Audacity. Many times in music, you get what you pay for, and if you have the money for a program like Logic, then by all means, go for it. But as far as acoustic music goes, these other programs will be more than sufficient.
  
  

Microphone

• Get a Direct-In box and plug your acoustic guitar into it to get the cleanest sound possible. Doing this will eliminate all background noise, static, etc. If you don't have an electric/acoustic guitar, then get the best microphone you can afford. You don't have to spend thousands of dollars, but you should probably spend at least a hundred. Check out some of the choices at mxlmics.com, and be sure to look in the USB section, so you can plug your microphone directly into your computer. Be sure to also get a pop screen to go with it. This will go a long way in smoothing out your sound.
  
  

Recording

• Make sure your microphone is not turned all the way up, because it will pick up too much background noise. But also be sure that it's not turned down too low, because then you'll have to crank it up in the mix, and this will cause static. Get the microphone input level as low as possible, but when you play back your recording, you should be able to turn it all the way up, get a loud volume out of it, and hear no static. You'll also be able to achieve this ideal situation more easily if you get extremely close to the microphone while playing.
  
  

EQ

• Equalize your acoustic and vocal tracks after recording to get the sound you're going for. Producers and mixers spend hours sometimes tweaking the equalizer options on their tracks until they get it just right. Also, it's probably best not to add any effects to the guitar, as these will usually make it sound thin and fake. The same goes for your vocals. A little reverb can go a long way, but try not to add too much chorus or any other special effects. Compress your tracks too. Look for the several preset compression effects that are available for each track. Many times they will say "vocals" or "acoustic guitar" right on them. Equalizing your tracks and compressing them will make the difference between a mediocre recording and a great one.