I'd suggest opening your Roth with one of the big three (Vanguard, T Rowe Price, Fidelity). Opening an account on their website is quite easy. Or you can call them if you prefer to speak to someone.
These three certainly aren't the only game in town but generally they will have the best funds to choose from, the lowest fees, & good customer service.
I agree with you. The best way to invest is to minimize the charges, so that you can maximize your returns. If a broker charges 2% management fees, it means that your investment has to make more than 2% or else you won't make any money on your investment.
In my opinion, do not put all $5,000 in a fund straight away. You can put $100 into a global equity fund, and $100 into a global bond fund. Do it monthly, so that dollar cost averaging comes into play, making your fund cost less. Also, by buying both the global equity fund and global bond fund, you are diversifying your assets, so that you still have money left in case of a stock market crash.