iTunes and iBooks

I'm trying to get a book to download..it's stuck in the starting position with no blue line.. But I can't delete and start over and when I try to restart I get " cannot connect to iTunes"... Although I have downloaded another book and music without a problem. Then went back to that frozen book and the "Cannot Connect to ITunes" sign comes up again .It has been charged through already too. I'm on an iPad 2 with ios6 .