craiglist scam help?

Hello, i posted an ad on craigslist selling one of my college textbooks for $35. someone(Cole Smith <[email protected]>) messaged me via email about the textbook and asked for my information so that he/she can send a check to me. " the email roughly said "I am not in town right now, but i will send you the check and someone to go down there to get the book." i replied with my information thinking that this person is true, but then they replied "i'll express mail the check to you and it will have a little extra in it, i'll give you an extra $50 for the inconvenience, and i'll have my mover come and get the rest... etc" after reading this message, i googled their email and found their name on a lot of scammer websites, so from then on, i stopped replying to their messages even though they continue emailing me. about a week later, the emailed me saying they delivered the check to my house via USPS. i got my mail and was surprised to see a check for $1,460.55. i haven't cashed the check, i haven't done anything yet. i was wondering what i should do?? should i rip it up? or email the person saying i don't wish to be apart of their scam and return the check?
thanks in advance for your helpful tips (: i don't want to be apart of any financial fraud, i'm just a college student trying to get by :/

File a fraud report with the postal inspection service. http://ehome.uspis.gov/fcsexternal/default.aspx You can also request an envelope from them and actually send them the check since you received it via US mail.

Thank you for the web address to file a USPS fraud complaint. Sent in a new one today. I'll keep hold of the check and wait for them to contact me.