Quick book integration with c#

i am looking for step by step quick book integration with c# library / asp.net project. i googled a lot but failed to find any good example that make sense except  this

http://www.mad-computer-scientist.com/blog/2008/03/25/quickbooks-integration/

but i am still confused  . i am looking for any solution from app creation in quickbook online to fetching data through quick book api. please help thanks in advance.