I would not recommend starting with $200. You could buy 1 share of AAPL and then sell it, and lose perhaps $10 or more (5%) to commission. You're down 5% on one trade. Do that a few times and you've got $150. With that low a start, commissions will be a high percentage of your assets.

My recommendation is to go work your ass off on a second job till you have a couple thousand and then start. In the mean time, read at the library or book store, learn more at youtube or tasty trade, and paper trade. Come back when you have a decent nest egg and you have 6 months of paper trading behind you.

I like thinkorswim as was mentioned above, but keep in mind that it can be very complex...

My new book is now available on Amazon. It teaches you my favorite trade for beginners. The pros use the same trade every day. Or, if you'd like a free quick summary of what's in the book, you can get it here.