its a good sport if you spend a lot of time waiting as theres always somewhere to do something. although if you're waiting for a job interview its not advised.
a few tips:work out how far you can jump from a stationary position and from running. count the distance with your own steps, putting one foot infront of the other so they touch. this way you can always know if you can make a jump.
start small and build up as you get more skilled.
never train alone as if something happens theres no one to help.
to gain maximum distance from a stationary jump: spread your feet to the width of your shoulders. crouch your knees to about 90 degree angles. put your arms out infront of you making a steeple with them which points towards your target. swing your arms back and forth a few times to find a rhythm. then jump, extending your legs and throwing your arms forward. these few little things usually get you an extra step or so.
when jumping up onto something/over something: tuck your legs right up as far as you can get them at the height of your jump. as your feet are higher you can land on something higher up.
put some masking tape between two posts or anything really to test what height you can jump over. if you fail you break the tape. if you fail on a real object you fall down to china town.
the best way to land is by doing what is known as a parkour roll: as you are about to land you should extend your legs and feet fully. its important that you remember to keep them extended softly though so once you touch down they arent rigid but rather flexible and able to absorb impact. always land on your toes 1st as this absorbs some of the impact. never land with your feet flat from a height as this sends more impact through you. once you touch down you should let your motion carry you forward and into a forward roll while bending your knees with the impact. its not a roll on your head but on your shoulder as much as anything. if you roll on your head you will hurt yourself. the beauty of a parkour roll is that it turns a lot of your downward motion into forward motion. this also means that when you come out of the roll you can come straight to your feet at a run. this is great for the freerunning aspect where you move swiftly through an urban environment as you dont stop after every jump. rolling on hard ground often hurts.
be cautious doing parkour at night as distances become harder to judge in the darkness and shadow. this is also true of the surface you are landing on/climbing up.
to climb up a high wall: an easy way to get up something higher than you can reach the top of is to 'run' up the wall. you should be able to take a few small but quick steps up a wall, allowing you to gain vital extra height. once you get fingers on the top you can pull yourself up. if you cant pull yourself up then you probably wont make it. try to check whats on the top of the wall. a mate once jumped/ran up a wall and grabbed the top. there were a row of nails on it for security and he had a matching line of puncture marks on his hands.
these are a jus few things that may proove useful. i trained with some seriously skilled people and i learned the techniques. everyone has slightly different ways of doing parkour. what ive written wont work with all people and some may not be able to do it. you must come up with your own style that fits you personally. this is a basic guide only. dont try anything here unless you can do it or have practised. train on grass with any method you want to learn. its not about finding out you cant roll after jumping from a height. find that out on the ground before hand where its safe. always be careful and you should remain uninjured. in parkour no one hurts you, you hurt yourself. bear this in mind always and be sensible. most of all have fun and be free. thats what its all about.
if you search online you will find several good sites. many have pictures showing how to do different moves (there are many moves) in stages.
http://www.urbanfreeflow.com is good. i used to train with some of their members a few years back when parkour was becoming known. they are highly skilled folk. youtube also has many great videos to watch. some are truely amazing.
anyways be safe, have fun. peaceout
but theres always race days for like £100 
. parkour costs £40 for a pair of trainers so its a good sport for the masses aye.
to all that are Training, don't give up 
on the APA ( Australian Parkour Association ) Sign up form, they basically say you can not try sue them if someone died or is paralyzed 
