How can a country attain the full benefits of its economic resources?

Rule one is never sell your country's assets. Grant leases in return for development of those assets with a percentage share of all profits made flowing into the government treasury. When the leases come up for renewal, make sure you get the best deal possible as all natural assets will eventually run out. Make sure that as far as possible, jobs created other than specialist skilled ones which may not be able to be met in the country, go to the local labour force to ensure the people of the country share in the benefits of the development. Use the profits from such ventures to invest in education, skills training and health care provision for the people and make it possible for people to a start up their own businesses with government help and advice where such businesses are viable.