Can I claim a past due college/school tuition from years ago for tax purposes?

I have a 20K past due balance from my college/school from 2006. I never paid this amount because I didn't have the money too, but now I do. I'm planning on paying this over the next few months and wanted to see if I could claim it on my taxes for next year, ie deduct it from my income so it lowers my taxable income? Thoughts? Suggestions? Also, what is Hope credit and the other forms of credits out there? Thanks!