Couple newb questions about opening an online brokerage account.

[Deuce2High]

Hey all,

I recently just started researching economics and the stock market. I have ordered some books on Amazon and I've begun reading and exploring the net; But I still have very little knowledge. However, within the next few weeks I plan on reading through a few of these books and I at this point I am planning on opening an online trading account that I can control myself to play around with (obviously cautiously and with research and advice from Dad and his broker). Some questions...

What do you all think of this plan in general? Is it too wreckless for me to open an account with such limited knowledge? Do all online brokers let you trade on all of the exchanges? If not, which online brokers will trade for NASDAQ, NYSE, and LSE? What online brokerage do you recommend? Is there any other important information or general advice for me to consider before I begin?