and what about them do you most appreciate? A paid site is okay to list IF it has good free resources. I am currently learning alot from reading Ophir Gottlieb's Livevol blog: http://livevol.blogspot.com/2012/01/understanding-option-skew-what-it-is.html He has hundreds of posts in the archives where he explains the interplay of option greeks. nasdaq.com and bigcharts.com both provide useful option charts if you don't have your broker platform open I like optionistics.com for these charts and the ability to quickly plot greeks: http://www.optionistics.com/quotes/option-prices http://research.investors.com/options-center/#General provides some useful option reports