Titles are fine, there is no copyright on them. You can use them anywhere and anytime without a problem.
Where you run into copyright problems is using lyrics from songs. So basically She Loves You - fine, no problem; She Loves You Yeah yeah yeah and you'd hit a copyright issue.
I'm using song titles as chapter titles in the one I'm writing too now, and it also has a few song lyrics smattered through the text. I'm not sure how potential publishers would look on this. I have a feeling that for a new writer, they wouldn't want the hassle of copyright issues. Also, I believe that if you do use song lyrics and incur copyright, the fee comes out of your pocket, not the publishers, so if you use too many it can get expensive!