This website is very useful when trying to understand why people buy stocks in general. It explains the risks and the rewards that come along with buying stocks. It also does a very good job of explaining market value and how much is too much for a stock
This news article is a good example of how people talk about stocks in the real world. It is a good thing to read to gain knowledge yet you can never trust anyone about which stock to buy without doing some research on your own!
http://www.investopedia.com/articles/investing/082614/how-stock-market-works.asp
This is a link to Investopedia which is a very useful website for all things stocks. This page in particular does a great job of explaining some key things you should be aware of when learning about the market such as volume and the bottom line.
This book is a very good introduction to stocks and gives a straightforward explanation of the fundamentals of stock market investing. It also gives useful advice on buying, selling, owning and diversifying. A disadvantage you need to watch out for is they usually only talk about the successful stocks and not the ones that hurt your portfolio.
This Youtube video is about trading and how the stock market works. It is very helpful for those who know nothing about the stock market or stocks. Yet for those who are familiar with stocks and the market it might be things you have already learned!