Vuru - Vuru is very easy to use, has a wide variety of data, and gives unbiased analysis (analysis based on numbers and not analysts opinions). The downside is they don't cover ETFs.
Google Finance - Charts are user friendly and versatile. Their stock screener does not work well. Typing a specific investment question into google is an invaluable and often overlooked strategy.
Investopedia - The best tool for a beginner investor. I probably use it once a week.
Yahoo Finance - Their stock center provides a lot of useful data in one place. It's great if you only have a minute to check the markets.
Is not responsible for your investments.