There are brokers that cater to frequent traders, and brokers that offer a wide array of mutual funds that you can purchase with no transaction fees. No matter what your approach to investing, there's a broker out there who can provide services that can save you money. The first thing you need to do is figure out what's important to you. All online brokers can let you buy and sell shares of stock, but here's where the similarity ends. Here are some points to consider.
Some firms have no minimum requirement to open an account.
If you don't have enough to meet the minimum requirement, you can strike that firm off your list. Most firms offer a smaller minimum for IRA accounts or custodial accounts. Transfer your IRA to the firm, and open a regular brokerage account at other firm, and you can avail yourself of services that you might otherwise have access to. The selection of funds varies from firm to firm, so make sure that a company offers the funds that you're interested in before you sign up. If you're not interested in funds, then you don't need a brokerage that offers a large selection.