I started out with Schwab ETFs. There are currently 13 ETFs available from Schwab that can be traded for free as often as you like with no minimums. Probably the biggest drawback of Scwab is they only have 13 available so it is a little more difficult to diversify. They also offer some very nice advanced trading tools such as StreetSmart. You can use this tool for free so long as you trade at least 3 times per month (and that includes the free ETF trading). You can also trade Schwab mutual funds for free as well, but as with all mutual funds you have to hold them for at least 30 days, or you could incur a penalty.
Fidelity’s EFT offering is even better with 30 different products available. Again you can trade an unlimited number of ETFs for free and there is no minimum. The main consideration with Fidelity is you need at least $2500 to open up an account. I spoke with a nice gentlemen there name Rolando (Phone 800-544-5115 ext 75020), and I get the impression the people that work there can do things like code in free trades for other products, so it helps to call. I would also note that with Fidelity you can trade mutual funds for free as well, but there is typically a 30 day period in which you must hold the fund, or else you get a penalty.
Also, with Vanguard everything is free all year long and they have 49 funds you can trade. There is no 30 day lockout. The ONLY catch is if you don't fund your account with at least $50,000 you have to pay a $20 annual fee for your money market account which you have to establish in order to trade. Beyond the $20, Vanguard by far has the best options.
And finally, you might also want to checkout TD Ameritrade. They have the most ETFs that you can trade for free, but the catch with them is you have to hold them for 30 days (like a mutual fund). So if you want to have a buy and hold approach, this would be a great option for you. They also have a nice comparison chart comparing them to the others (but don’t tell you about the 30 day lockout period)
I hope this info will be helpful to some of you.
Best Wishes to All!