Welcome Steve! I'm leaning towards a Roth IRA with Scottrade as well!
I would please do your research first, on what kind of investing you would like for your Roth, and THEN pick the best investment firm for the job. Of course, before that, you'll also want to clearly define what it is that you're trying to accomplish with this Roth. (Most likely, it's retirment, but that's not always the case....)
I second noppenbd's suggestion with Target Retirement Funds.
It's the easy way to to start out and start out right.