If you already have an account that you'd like to transfer to a discount broker from a full-service broker or an offline bank, it's simple. Your new online broker will provide forms and procedures for making that transfer. Don't forget to ask about any account transfer, closing, or opening fees -- both your old broker and your new one may try to charge them.

Before you make the transfer, you'll need to decide whether to sell all your current stock holdings or transfer the shares directly to your new account. Stock transfers are more complicated and may involve higher fees. And selling all your stocks can leave you with a big tax bill, even if you buy them all back in your new account. Be careful, and consider all the consequences before you decide.

If you wish to transfer only part of your account -- that is, transfer some money from an existing account without closing it out completely -- contact your old broker to get a check cut for the portion of money you wish to withdraw.

And if you're switching from a full-service broker to a discount one, don't let your old broker talk you out of taking control of your own money.