Led Timer Query

i am working on a reaction timer that measures in seconds and miliseconds how long it takes for a button to be pressed after the user is told to press it. i would like to know if anyone could offer some advice on how to make the pic16f877a do this and what circuit is best to do this with( i intend to use large led segment displays to display the results). i have purchased an easypic 4 board to experiment with and the timer is the only part of the project i havent been able to finish due to my own lack of understanding. thanks in advance for any help you may offer.

Search this forum for olympic timer. You should be able to find a good starting place. There are several very nice examples.