what is the best way to lead convert in to sales to survive in the web development market? what ?

Hi, I am a owner of a 4 years web development company. I am technical and not too much. I just need to to get project from international market. i have given ad on google and yahoo. if i get enquiry from the people. I am not able to convert them as customer. Please advice what is the best way to give actual Pricing so i can survive in the competive market.

your main need is your English.

find a native born English speaker with a degree in business from
an American university.