Well, most "free" music is stolen and in breach of copyright and we can't give you advice on that here, I'm afraid - it's in breach of the forum rules.
To be honest, though, the best way to buy music in my humble opinion is to buy CDs and rip them. Music you buy online is a) encoded in a lossy format and b) hedged about with restrictions on how you can use it. Buy the CD, rip it yourself to your chosen format and your chosen bitrate, then you've got the non-lossy hard copy (the CD itself) as a back-up. I like iTunes for ripping music but others will have other suggestions.