From my 200+ games experience with Tryndamere and friends suggestions I present you this guide .
It's not very good but it does some stuff :] please comment and if there are any mistakes tell me to edit :)

Tryndamere's spin can go to the otherside of the walls and cover's great distance so it's a must have in 3v3 and 5v5 ( Thou 5v5 Tryn s*cks ) then take Mocking Shout IF game is going well and you have lotsa life otherwise take bloodlust to heal yourself. When chasing use mocking shout is enemy chases do NOT use mocking shout because you will stop for a lil and not slow them because they must have their backs turned for slow to activate so spin when they try to gang or kill you. Also Trynda is very good for 3v3 spin once when going out of the stairs to keep some time when you have arrived at the bush the cooldown must be ok so if enemies are already there use it to run if not camp there and wait for gang and keep spin to steal first blood to take the Dagger ;D . And always keep is mind the extra dmg per % of life missing bloodlust gives which makes a PERFECT combo for ulti( triple kill alone once xD ) also if you get feeded you have the most chances for winning ( unless they start 4v1 to feed theirselfs, which is something you can counter by all staying in a single lane and all together ) . Mocking shout can slow enemies and make them deal less damage it can also harass them . And something last DO NOT jungle with Trynda at low lvls unless you have runes, masteries and abilities especially for that.

For runes focus on full attack damage even glyphs it helps early game and they Items I entered above :)

As for masteries focus on FULL DAMAGE lower time spend dead so you can join the battle faster and a little bit of armor ( and yes he needs some of that too xD even thou ulti can cover up for it )

Flash - It can help you chase or run when spin in cooldown, go to other sides of the walls (even thou spin does same work and with longer range)
Ignate - The second spell I suggest for Tryndamere because you often will find yourself with low life and can't tower dive espesially in first lvls where there is not ulti ignate can finish the job for you and get you a kill :]
(Alternative)Exhaust - Exhaust can slow enemy and make him deal very little dmg if AD some dmg less if AP and can also slow target which can make you win some battles that for example enemy is feeded.

I don't suggest AT ALL revive or heal for Trynda since he must be full attack dmg

Once the game starts grab ASAP a Brawler's Glove and 2 health pots and head also asap to your lane to set up ambush for the enemies if you done well and took first blood and Dagger for attack speed and turn it into Berserker's Greaves then turn Brawler's Glove to Zeal and then to Phantom Dancer since Tryndamere is carry attack speed and critical's are very imporatant then grab an Infinity Edge which gives AD , Crit and Crit dmg then Bloodthirster for life-steal ( take Bloodthirster after Phantom dancer and Infinity Edge because life-steal with no dmg is nothing) then take in ALL rest slots Infinity Edges which are VERY VITAL for Tryndamere because they boost his passive which gives crit chance.