You won't get a pro sound. Period. If you could, why would people ever spend a penny more than 40 bucks, let alone hundreds of thousands building studios?
This thread has been sarcasm'd out, so I'll give you some real advice:
Audacity has been mentioned. Go download it. Do you have Rock Band or Guitar Hero 4, by any chance? If so, plug that mic into your computer. Press record in audacity, and bam, you can record for the cost of absolutely nothing. If you do not have a USB mic, you can pick one up for pretty cheap. In fact, can you loan 5 bucks from someone? If so, you can get this one at your local radioshack. Not the highest of quality, but this way you don't need to buy a preamp or anything. If not, you'll be able to find one a little cheaper. You'll want to save up for a mic stand, too.
Also, talk to your dad. If he was in a band, he might have an old 4-track laying around somewhere. Or, he might know somebody looking to get rid of one.