Reading over the bottom portion  of the graph is very important as it will allow you to gain a breif overview of the company and its preformance. 

Looking at a graph in candlestick mode allows you to capture details, and price fluctuations more easily than other modes why is why you often see many people viewing the chart in this mode.

 Some crucial patterns and fluctuations of a stock can only be seen in this mode which can make a huge difference when trading.  

Reading the news is very important for investing, as any huge news realted to the company can cause the stock to go up or sink.