Start with adwords keyword tool. Know your business, know your competitors, find their keywords, use them. Adwords bidding is based on the Vickrey bidding system so if you have a strong mathematical background research this system to set your pricing. Next develop several landing pages and use Google Analytics to test them. Finally, develop your campaigns properly, this is one of the most important keys in getting a high CTR with a low CPC. Do it right, and you will pay much less than your competitors while converting many more customers. It is not unheard of for a well run campaign to generate over 5000% ROI.
Originally Posted by Delhibudget