Kudos to John Forman, who has assembled an edited volume specific to the questions most asked by developing traders. A variety of experienced traders and market bloggers have participated in the volume, offering a mix of viewpoints. It is often quite difficult for new traders to obtain impartial guidance in starting their careers, so such resources are quite valuable. The topics for the questions range from trading mechanics and trading psychology to market analysis and trading careers. Good stuff!
In general, I would highlight three areas of learning that I would want to have if I were looking to start out as a trader today:
1) Macroeconomics - I would want to have a grasp of intermarket relationships and how monetary policy affects interest rates, currencies, and economic growth. This information may not determine the trade over the next half-hour, but it does govern the market's longer time frame picture and help determine market trends. A lack of understanding of macroeconomics and intermarket relationships has been a major reason many short-term traders have lost money fighting the market over the last few months.
2) A Trading Theory - A trader needs a framework for thinking about price movement and making sense out of the steady stream of price changes across markets. I'm not sure that it matters greatly whether traders subscribe to one theory or another, but I am certain that having an explanatory framework is better than not having one. Personally, I have found Market Profile theory to be an especially useful way of conceptualizing market action across time frames. Other people find Elliott Wave theory or any of a variety of technical analysis frameworks to be useful.
3) Observation - Hands down, the smartest thing I ever did when learning how to trade was to watch markets for a long time before trying to trade them. I collected charts of intraday action and, each day, looked for the best trading opportunities. Over time, I started to see repetitive patterns among those opportunities and those became important to my subsequent trading. Watching not only price, but volume, sector behavior, intermarket action, and such measures as NYSE TICK help you recognize the dynamics of breakouts, reversals, and trends.
Knowing what I know today, if I were starting out as a trader or advising a beginning trader, I would advocate at least a full year of learning, observation, and practice trading before putting money at risk. I strongly believe that a major reason new traders don't succeed is that they fail to put in the necessary time to learn markets and acquire skills.