Tryndamere is one of the deadliest late game dps champions ingame.
DPSing with Trynd is very easy. Rightclick and enjoy the crits. He is easy to play but hard to master. He is a great early game laner, with nice self heal, good escape mechanism, and build in slow, paired with no mana usage, should let you lane extremaly long. The Early game is the hardest part since your crit rating is quite low so getting crits for self heals will depend on your last hit skill. If you get harrased much you will still be viable coz of passive that increases your crit rating ALOT when you are low on HP, you can try to stay in lane even on low hp and last hit/crit minions on your tower to benefit from lane exp as much as possible. Be very carefull. In mid game you will pwn each and every non tank champion even without lifesteal. Jungling with high crit and self heal is easy as pie. You can start roaming with just phantom dancer and boots. In 1v1 with your ulti, you will be the biggest threat on the map. Watch out for tanks.

Pros
+ One of the best endgame dps champions
+ Great healing ability (Bloodlust)
+ Great escape/tanking ability (Ultimate)
+ Can go through walls (Spinning Slash)
+ AoE Slow ability.


Cons
- Squishy early game
- Requires good timing and some skill for good use
- Vurneable to DoT's, Blinds and Thornmails :)
- Dependable on only physical attacks only.
- VERY item dependant