Yes this possible, and very easy. First, open up a new garageband project. Then, go to "TRACK" on the tool bar, and then go to 'NEW BASIC TRACK". Next, in the bottom right hand side of garage band, there is an icon that look like a couple of music notes. click on it. This should open up a side bar in garageband. Now click on the triangle to the left of "itunes", at the top. Scroll down, and pick your songs either of a playlist, or all of your music. click and drag the songs into garageband one by one, and split the song up so that you have the part that you desire, and delete the rest.
To split the songs, highlight the music file by clicking on it, and then go to "EDIT" "SPLIT".
hope that helps.