Stocks generally perform well over time. With that being said you should pick up a book and read. Currently I'm reading the intelligent investor by Benjamin graham. I'll give you a little insight; There are two types of intelligent investors: one is the defensive investor, while the other is the aggressive investor. When picking a stock it's always best to understand what the company is and how it works as well as getting a firm grip on the financial statements of the company. What your looking for is mainly positive growth and higher income than debts.
With that being said, you can choose to be the aggressive investor, which would require a lot of time and dedication to finding the deals (stocks that are generally priced lower than their market value). If, however, if you don't have a lot of time to dedicate to researching and sifting through stocks daily then I suggest going the route of the defensive investor. My recommendation for the defensive investor would be to find an automatic investor or broker who will take care of funds for you while you basically do no work at all.
This is just a tiny glimpse of the "ART" of investing. Aggressive and Defensive investing goes much deeper than the above paragraph and I could literally spend all day talking about investing without making much of a dent. Again the best advice I can give you is to start reading books on the subject.
Knowledge truly is the most valuable and treasured possession.
On another note remember that emotions are the enemy when it comes to money and investing. The trick is to buy low and sell high. So it's safe to say that the state the market is in (Bull market) is pretty high and it's probably going to be harder to find a deal right now, not saying they aren't still out there. It's usually the older companies that lose interest at this point and funds go to other prospective growth funds. After the bull I might suspect that the older companies will flourish again because of the bear market taking hold. I suggest you take that with a grain of salt because I most definitely can be wrong.
It really can get complicated if you don't know what your doing, the worst thing you can do is become the speculative investor whom only invests on whim or "rumors" especially from professionals without fully knowing the company.