FIFA Soccer 09 Message Board  

On PC you can do trick easily if you play with mouse. Just press middle mouse button and move mouse in various directions. As for keyboard I don't know yet.

here is a very good guide on how to perfrom tricks in the PC version of fifa,its really useful and contains almost all the tricks in fifa 09 if not all and what key combinations you must press forums.electronicarts.co.uk/fifa-09-pc/341891-my-fifa-09-pc-guide.html