As you can see ISTP, there's 2 types of trading; Fundamental trading, as tzu mentioned, and technical trading, as Jake mentioned previous. You can do both of course, you may find yourself favoring one over the other.
I'm in the same boat as Jake...technicals all the way; scalping, day trading and swing trading. You don't have to go as in depth with the fundamentals, but you do have to be aware of economic news releases. It can be easier at times as you usually are trading indexes or ETF's, instead of plunging deep into a company's books to see if you like their product & numbers. It's up to you.
Questrade seems to be the cheapest. You can keep your funds in US$ or CAD$, so that you do not get dinged a forex fee for every return-trip if you're buying US markets.
It offers stocks, options, bonds, gold, and mutual funds, in both US and Canadian Markets. Also you can trade with your TFSA at most brokerages.
Getting Canadian market data can be a pain in the butt. Most brokerages will charge you extra or you must be an active trader to get it free. For this, I usually trade US markets. All of that stuff is free; real-time charting, level 2, etc. I chart with Thinkorswim (the best free platform) and keep my questrade window open (basic platform) to make trade entries. This is really only important if you're daytrading. For buy & hold, your basic level 1 quote, and a 15-minute-delayed chart is fine.
I've started reading "The intelligent investor", but it's not for me. It is more traditional 'buy & die' type of investing.
For a good taste of technicals, have a look
here for daily videos.
Good luck moneybags!