It can be anything, a regular post, an interview, a how-to, a review, or whatever, just paste up a link to it along with a couple of lines about why it's your fave and we'll pick nine winners at random from among the entries (and it'll be random who gets which prize).
For example I could upload my eBook to the public folder on Dropbox and grab the link it gave me so that I could paste that into my blog and anyone could download it.