congrats on starting. Check out stockdoubling.com
Go to your local bookstore in the Stock section and just see what interests you. As far as specific questions on the company. Go to yahoo finance and type in the symbol and look at some of the news. Usually at the bottom of the news they will say an investor relations person to contact etc.. Just call them up and see.
At $200 their is no point in being diversified. The commissions would eat you up. I don't know much about sharebuilder but make sure they don't have a lot of fees. I would recommend Scottrade.com you can setup an online account for $500. But I bet if you sent in $200 or went directly to them with a $200 money order they would probably get you setup as well.
Have specific goals to get out of the stock (assuming you don't plan on holding for years) so if it hits 50% or 100% or 20% whatever you take some profits etc..
The key is to have an exit plan when you enter the stock. That way you don't fall in love with the stock and you know you will get out at X no matter what. So have a profit target and a stop in mind.
That would be my advice. Take care.
check out www.StockDoubling.com
I started with $550 back in Oct. 31st 2005 (16 months ago) Today that account stands at $5775. (17,500 shares of ATSX at .33)
That is a 1050% return in 16 months. It can be done but have good idea of what you are looking for.