In order to open the account you will need to tell them how you would like your money invested. This means you will have to choose one or more of their mutual funds or choose individual stocks if your IRA is a Fidelity brokerage account.
A Roth IRA is a self-directed investment account. That means there is no option for payroll deduction. You can make deposits to your Roth account using the Fidelity website (transferring money from your bank electronically) as you see fit or you can set up an automatic investment plan.
As far as what "most people" do about lump sum vs. monthly deposits...it varies from individual to individual. Statistically speaking your rate of return will be higher if you can do a lump sum at the beginning of the year rather than space out the deposits during the course of the year. That being said, when there are big dips in the market it's nice to be able to plunk another chunk in...it's like getting your stocks on sale!
P.S. Many employers who offer 401k plans also offer a Roth 401k option. If you are also contributing to a 401k through your workplace you may wish to inquire whether they also offer the Roth option.
Some are payroll deduction, some are not. If your employer doesn't offer the payroll deduction option then you have to arrange the deposits yourself. The monthly deposit option typically works best. Otherwise, unless you make a ton of money, you will have to save the money somewhere until you have the total amount. You might as well save it in the Roth since that is where it will end up anyway.
You make the deposits (called contributions). It doesn't come out of your paycheck. You can contribute monthly or however you wish.
I want to create a Roth IRA account. How does I Roth IRA work? I know it's after tax so I don't pay taxes at retirement and the current limit is 5500 per year. Does it come out of my paycheck every time I get paid like a 401k does? Or do I have to transfer money from my bank account to a Roth IRA, if so, do most people just deposit one max amount ($5500) at the beginning of the year so they can get the most interest?
