To monitor the performance of your ads and campaigns, you should:
Customize, generate, and save report templates that cover your key business metrics
Schedule reports to be regularly emailed
Implement conversion tracking for purchases, key page views, and other events that are significant to your business model
Start a Google Analytics account that is connected to your AdWords account and add the Google Analytics JavaScript code to each of your pages
If you maintain a WordPress blog, add an Analytics plug-in
Create funnel analysis reports for each of your key conversion areas
Use Google Analytics overlays to understand the behavior of visitors as they pass through your site
Consider implementing page comparison tests to see which pages work better using Website Optimizer