TrendSpider.com is a simple to use charting and indicator engine. You can test out indicators and parameters to refine your trading strategy's buy/sell engine. After performing a strategy test, you can set it for live trading alerts to help trigger buy/sell action. I use their easy to see charts in my presentations and website.
Investing.com is an excellent collections of all things trading. There's news, analysis, charting, prices, webinars, portfolio tools. Worth at least taking a tour through the features.
An alternative to Amazon.com books with free delivery worldwide. A UK based operation with outlets around the world, I found the price of my own book, Panic-Proof Investing, less expensive here than on Amazon.
CSI Data is good for end-of-day data for research simulations, expecially for futures price data, their original sweet spot. Reasonable prices, reasonable accuracy, and some very old data.
Investopedia has a collection of formulas for most common trading indicators, return-to-risk measurements and lots of educational material for the new and experienced trader.