Follow the Navigation in above title on your Google Webmaster Tools account. Webmaster Tools-->Your Site On The Web-->Search Queries-->Top Pages. Scroll down to where it shows the URL's of the top pages for your site.
There will be a graph showing the Statistics for
- Impressions-How many Times those pages showed up for Keyword Queries
- % Change-Shows you up or down the % of change for each Statistic
- Clicks-Shows you how many clicks there were for those queries
- CTR-Click Through Rate-Shows how many click over to that page
- Avg Position-Shows average position of a given page for the queries on the Organic Listings
You can then take some of those keywords and put them in your:
Meta Tags, Head, Body and Footer to finish your keyword optimization for that page.
I then made a categories and keyword text description bolding the main keyword or keyphrase for that page and used in the URL towards the bottom of the body section.
Next I took those keywords and made backlinks from blogs,forums and Social Networks and started a mini link building strategy I always use.
If you have a product or service you need conversions on, then I would suggest putting "Buy Now" in the Link URL or in the Code In Context and if you have a Local Business put in a map to your store location using Google Maps.
In closing; webmaster tools has allot of features you can use to properly optimize using their tools, its just a matter of taking those tools and further analyzing their results for better analytics which in return helps you to better optimize each page for higher organic listings in the SERP'S.