How to Buy Stock Online Immediately

Sign up for an account through an on-line brokerage company. There are links to 'E*TRADE,' 'ShareBuilder' and 'Zecco' below, but there are many more to choose from. Click 'Sign Up,' and follow the prompts to complete your registration.
Transfer money into the brokerage account. This will normally take one business day to be processed and appear in your account.
Once the money has posted to your account, find the ticker symbol of the stock you want to buy on the site's research page. Once you know the symbol, go to your site's quotes page, type in the symbol and click 'Get Quote,' or your site's equivalent.
Select 'Buy' once the quote comes up. Select the amount of shares you would like to purchase. Then you will be asked if you would like to place a market order or a limit order. With a limit order, you set the exact price you want to pay. A market order buys the stock at the price sellers are asking at the moment.
Confirm the trade when your site asks you to, and in a moment you will receive a notification that your trade was accepted or declined. Your trade will usually only be declined if you do not have enough funds to cover it.

How to Find the Cheapest Online Stock Trading Sites

Run an online search to find the cheapest online stock trading sites that are available, using a search engine. You will probably find many advertisements during your search that will point to some of the lowest cost providers that are available. Some may even offer a special block of free trades for signing up with them.
Read reviews of various discount online brokers posted by financial websites and blogs. Understand that some of the reviewers may be financially compensated for the review or paid based on any affiliate link provided within the review. Regardless of the intent of the author, these reviews often contain some quality information that you can use to help you make a your selection of the cheapest online stock trading site that fits your needs.
Look for comparisons of the cheapest online stock trading sites that are included on reputable financial websites. You may be able to find a breakdown comparison between similar online discount brokers that lists specific costs and included tools. Consider all factors when making your decision between seemingly equivalent online brokers.
Open up an account with the minimal initial required amount of money and test out online discount brokers on your list of potential sites. One of the best opportunities to learn and educate yourself is through personal experience. You can find the cheapest online stock trading site that is the best fit for you by testing out several sites and staying with the account that you like the most. Once you have decided on one or two sites, you can close out your other accounts and transfer your funds into the one that you picked as the best.