It is very small framework but I think it has all needed things for building website. Also it is very light, you can see it on main page of Sinatra Framework that has example. It has good documentation full of examples. Also I found out that Heroku helps Sinatra. You can try it be tutorials that I found: net.tutsplus.com, titusd.co.uk. Sinatra has two books "Sinatra: Up and Running" on Amazon (you will find tutorial when you would read last chapter so I build it and you can watch source code github.com) and another book on Sinatra website.
Sinatra really cool web framework that has good support.