Start with 0.00 and paper trade, once you know what you are doing and are ready to put in money, put enough in to make you care about your decisions, but not enough to cause you sleepness nights, i like a little stress to keep me paying attention, but not too much. what figure that comes to in pounds and pennies is down to the individual and their circumstances. Aspects of your plan should tell you whether or not its enough money to trade the particular market/broker.