From my experience with mini sites, i create two or three good content pages along with the usual such as contact us, privacy etc, etc. (i do as much on page seo as possible)
After google has indexed the site, i then do some slow off page seo and monitor the results. (I am careful not to get too excited about the google honey moon period, where your site will temporary rank high up in the results then fizzle out).
After a short while i will add new content / pages depending on how good the site is ranking and how serious i am about the site. I have personally come to the conclusion that running sites that pose no interest to me are a complete waste of time because i just cant commit or put the time they require to rank high.
Good Luck
Lee