The click rates depend on demand from your competitors for the keywords. Expect the average with a cost-per-click price of 20-50 cents, with high demand keywords (eg from the travel, IT and insurance industry), the cost-per-click price for $1 to 2  lie. The better the design and text of your ads and the selection of keywords, the higher the click-through rates and thus the number of relevant visitors to your site. Even with small budgets can significantly increase your visitor numbers are achieved!