The last year and a half have shown that the stock market in not a place for the weak at heart. It is important that you never invest money in stocks that you can't afford to lose. So many people had their life's savings in stocks and now they are in real trouble.
Stocks are risky and any stock you buy can go up or down no matter how much it is recommended. Anyone who tells you that investing in stocks is safe is not telling you the truth. If you want safety, you should be investing in bank CD's or government bonds but of course right now they are paying next to nothing in interest. You may get a higher return with stocks but the much higher risk comes with it.
The last 10 years or so have seen stocks become much more volatile. One of the reasons for this is the emergence of online stockbrokers and the ability to buy stocks online. Day traders have emerged that are interested in buying and selling stocks quickly rather than invest for the long term. This has made the stock market have bigger swings day to day. It used to be that investors bought stock in a company because they liked its fundamentals for the long haul but now many buy stock with only the short term in mind. It has almost become too easy for anyone to get involved in the stock market and as a result a lot of beginner investors have gotten involved.
If you are new to investing and stocks, you might end up scratching your head trying to learn all the terminology. Anyone who watches any of the business shows on TV will hear a lot of technical terms thrown around which will probably be very confusing. You must realize and accept that you will never be able to learn everything overnight.
Your best bet is to get a book on the basics of stock investing and then start to learn the vocabulary and terminology. Know that this will be a long term endeavor but one that will be worth it. If you go about things slowly and keep learning from the ground up, you will soon be in a position where you will understand what is going on in the stock market. You will then start to understand what type of stock investments you are interested in and what types you will want to steer clear from.