Find a good online stock broker and open an account. Become familiarized with the layout and to take advantage of the free trading tools and research offered to clients only. Some brokers offer virtual trading which is beneficial because you can trade with play money (see #9 below). A great tool for comparing online brokers can be found at StockBrokers.com.
Stock mutual funds or exchange-traded funds. These mutual funds let you purchase small pieces of many different stocks in a single transaction. Index funds and ETFs are a kind of mutual fund that track an index; for example, a Standard & Poor’s 500 fund replicates that index by buying the stock of the companies in it. When you invest in a fund, you also own small pieces of each of those companies. You can put several funds together to build a diversified portfolio. Note that stock mutual funds are also sometimes called equity mutual funds.
Worth noting: A 401(k) is a type of investment account, and if you’re participating in one, you may already be investing in stocks, likely through mutual funds. However, a 401(k) won’t offer you access to individual stocks, and your choice in mutual funds will likely be quite limited. Employer matching dollars make it worth contributing despite a limited investment selection, but once you’re contributing enough to earn that match, you can consider investing through other accounts.