Trading Stakes

I am interested in trading on the premier league winners market. The ammount of twsts and turns surely make this a brilliant market to trade on.

I have neveer traded properley before so was wondering if anyone could give me a rough idea stake sizes. I have read somewhere and can't remeber where a guide for stakes at certain levels. Things like if the odds are over 5.0 only stake this much as the fluctuations can be too costly.