I’m a new user so don’t know alot. I intend to sign up with amazon, yahoo or limewire when my credit card renewal comes because i’ve found that iTunes doesn’t exactly have an exhaustive library of songs for many artists, or they have only one version of a song.

Question: Will I encounter obstacles when downloading from other sites such as getting the songs onto the iTunes library? Am i going to have to store them somewhere else? What should i expect to see?
Thanks.