Watch some tutorial videos, go out and try them! You'll learn! :)
EDIT: This is a good one http://www.youtube.com/watch?v=h-6v4ho9n... and you can find more in the related videos :)
Hey man, what's up. I always love to see new people interested in parkour! I actually made my own website geared toward new practitioners like you after answering so many questions on here. It's not done yet though so there isn't a whole lot on there now but I think it can help give you a general idea on what parkour is and what your training should generally consist of. You can check it out @ parkourelements.webs.com
In the meantime though I suggest you check out some other groups online such as Flow, Parkour Generations, Fifth-ape (Colin Pistell), Team Tempest, and Parkour Visions.
Hope this helped and if you have anymore questions then please feel free to e-mail me. My contact info is on my site under Contact Us.
My boy and me used to do this for fun but we wouldnt say we were free runners.
a group of local boys have started a club there getting quite good try renfrew parkour on you tube.
they started off at the local skate-park so maybe worth trying there otherwise grab a m8 and go for read books watch videos e-mail people for hints tips etc
Just practice and see if u are good at it if u are start video taping ur tricks and put them on YouTube if ur really good someone will see it and that's how a lot of ppl have been discovered is by posting videos of themselves and some are famous now
Make sure you have good health insurance and get on good terms with your orthopedic surgeon.
Then, go jump over things.