It depends on the niche as NGO's still provides a large scope. For instance if your NGO's is a non-profit I would immediately go to: http://www.google.com/gran

It depends on the niche as NGO's still provides a large scope. For instance if your NGO's is a non-profit I would immediately go to: http://www.google.com/grants/ http://www.google.com/grants/ and apply for the $10,000 per month Adwords Grant. After that I would start by reaching out to sites listed in: http://nonprofit.alltop.com/ http://nonprofit.alltop.com/ and http://www.businessesgrow.com/2011/05/08/the-worlds-best-non-profit-blogs/ http://www.businessesgrow.com/2011/05/08/the-worlds-best-non... I would reach out to them with the intention of getting a post written about the non-profit in them and/or offer them a guest post to post on their websites.