An exhaustive list of investment strategies is impossible because they are as individual as the people who employ them.
As a new investor, however, you should be aware of some of the more popular (and saner) methods people employ for investing in their stocks:
The recommendation strategy:
A recommendation is advice or information, sometimes unsolicited, received from other people who may possibly have better insight into the stock than you do.
Recommendations are a wonderful source of information as long as you know their source and the recommender's expertise on the subject.
The research strategy:
Any investment decision you make should require some research. The extent is really up to you, but the time you are willing to contribute toward being ultrafamiliar with your investment decision correlates absolutely with the investment's success. By cheating on investment research time, you are ultimately cheating yourself. Make no mistakes about it; this kind of cheating will cost you cold hard cash.
Buy and hold:
Buy and hold is an investment strategy whereby an investor purchases a stock and leaves it alone. Buy and hold usually implies that dividends will be reinvested in subsequent purchases of the stock.
For a buy and hold strategy, you would want to consider stock in companies that have the potential to be around for the long term. Consider blue chip stocks or stocks with good growth potential to achieve this. In addition, instead of collecting dividends, newer investors should seriously consider reinvesting their dividends into subsequent stock purchases. Many companies will execute these subsequent purchases without adding sales loads, making the investment even better. In addition, by negating broker fees and allowing compound interest to perform its magic on the initial investment and its subsequent dividend reinvestments, even the most novice investor is better placed to realize a profit.
Mix and match as you see fit; take what you want and leave what you don't like.