MP3 Player to speakers

Hi
im trying to hook up and mp3 player to a set of speakers. the MP3 player that i think i am going to use is the Creative Zen Mozaic 8GB - as its the best i ould find that has a big enough space on it and long enough to run with out having to replace the battery every year or so.
the thing i want to know is what amp should i get to go between the mp3 player and the speakers as i dont think the mp3 player is going to have the kind of output i want.

thanks