This is the first build that I have ever created. So please anything that is wrong/left out throw that down there in the comments!

Tryndamere was one of those champions that sounded really fun to play. Big crits, lots of crits, heals himself, able to tell death to go away and looked like a champion that could just go to town on people. The big problem with him was, he was melee. I had a big problem with melee and only liked ranged champs due to my playstyle. Finally broke down, played Tryndamere and instantly fell in love with him. There is just something about getting jumped, or jumping into a 2v1 and being able to at least take out one of them for sure and get away with it if you didn't kill the 2nd champion.

I plan on keeping this build updated everytime there is a change so if you like this build and follow it, help me by double checking things if they get changed.

Pros
1. You are able to spin through walls to save your team or get away
2. Insane crits and HIGH damage
3. Able to 2v1 and live
4. Self healing
5. One of the fastest champions endgame
6. Runs off health as your resource.

Cons
1. Very slow at the start of the game
2. Very item dependent
3. Melee, so you are still able to be kited fairly easy
4. Seems to be focused first and for good reasons.
5. Runs off health as your resource.

I put the last one as a Pro and a Con. You have no worry of running out of energy or mana and waiting for it to refill or getting items to speed that up. At the same time to, using them early game can bring you closer to death so you have to be careful.

I personally look at the Summoner spells as what your play style is and what you like to run. I feel that there really is no "Right and wrong" answer for most of them. I will tell you what I run, and what I feel should NEVER be taken with Tryndamere.

Spells that I take personally

Exhaust I take with him as it slows them, lowers the attack/magical damage they can do and I talent into it allowing the spell to last longer and also lower armor.

Flash I take for the ability to flash through larger walls, catch up or get away from people.

Spells that you should NEVER take on Tryndamere

Revive, this spell has no practical use and has a SUPER long cool down.
Smite, we are not jungling with him so this is of no use.
Clarity, if you even think about taking this for Tryndamere I am truly sorry that you have lost logical thinking.
Rally, you are going to be getting enough damage done that will make this worthless.

Again, the rest of them are how you play and what you like. I can not say that you HAVE to take this to be good and if you don't then you will fail. Play around with them and find 2 that work well with you.

19-0-11

Havoc is terrible as it's +% to your BASE damage. That is without your items. So 115 at level 18 + 5% to that makes your base damage 120. That's not enough I think to waste a point into. Specially since Tryn wants to crit and crit hard.

Only 2 points into the Cool down Reduction because you are going to be crit heavy. Crits lower the CD on Spinning Slash. As stated later on, you will see why Spinning Slash is a VERY handy ability.

Utility Master is something I love to benefit from. Red buff and Baron buff being able to hold those longer will get you a few extra kills.

I'm going with the Greater mark of Malice, Greater Seal of Malice and Greater Quint of Malice because with Tryndamere you want and need to be able to crit very often. This will raise your Bloodlust, your bread and butter to this champion.
The Greater Glyph of Alacrity is there because being able to attack fast with a very high chance of crit means that youll always be stacking your bloodlust and being able to use it's active to heal yourself and stay in a fight much much longer and kill the other champion much faster.

Brawler's Gloves and then 2 Health Potions. The gloves are cheap starting and gives you crit along with the 2 pots that are going to allow you to stay in your lane long enough to get your Bloodlust and then its very difficult to get shoved out of the lane.
Berserker's Greaves Remember we are looking for crit and attack speed with this build. The attack speed here is great with the 2 movement speed. You have Spinning Slash and mocking shout. You should have no trouble keeping up with any champion mid-late game.
Avarice Blade. Ok, I know that those gold/5 items are not that great. But the Brawler's Gloves build into them. You are getting a bit more crit now and are getting some gold over time to help with your next item. This should be sold to get the next item once it will sell for enough to put you over the build price.
Infinity Edge. This little item here is where you really start being a power house. It's expensive so you have to remember to last hit and also why you picked up Avarice Blade.
Phantom Dancer What's not to like with this item and Tryndamere. You get great attack speed, crit and decent movement speed. Attack speed and crit, exactly what we want here.
Stark's Fervor this item is mainly to help in team fights. Give that bit of edge to your team so you can just plow through the enemy and survive the fight. I'm sure there is better, but for its price and how much damage we are throwing out now I love this item.
The Bloodthirster This is where you add the insult to injury. You are already hitting really hard, critting like a madman, lifestealing and now you are just going to go on killing sprees and get those stacks and turn into a tank that carries your team.

This allows you to clean up creeps faster and get the last hit on multipul creeps if need be. It is also a good escape ability as it sends you spinning out of range. If the other team is overextending or playing defensively you can use this to harass them and get yourself to zone them.
Zoning someone is when you push them out of the XP and gold range. Effectively making them stand there and not be able to level. Don't expect to be able to do this every time and when it does happen be ready to get pushed back by both enemy champions. Once they go to jump you your Spinning Slash allows you to fly through the creeps and stay safe along with hitting the enemy creeps and possibly getting some last hits on them.

Bloodlust is what you will want to max first. I can not strees enough how awesome this ability is. There is just something about standing there farming creeps, getting attacked by an enemy champion and just popping this to heal back everything you just took. Not to mention that as you stack the Bloodlust you are hitting harder.

Mocking Shout is one of those abilities that has amazing use. You can lower all surrounding champion's damage. What more can you ask for with that? But there is more. Having all enemies with backs to you ALSO get slowed. This lowers the damage, and then allows you to catch up to them. One more great thing about this ability. It will trigger when enemy champions are around you. No need to face check bushes, just watch this ability.

Undying rage. This just tells death to go away. After you have put 3 points into it, once you pop this you get 8 free bloodlust stacks. Stack this with your passive of Battle fury and nothing will be able to stand against you. You can pop all 8 stacks to heal yourself and then build the stacks up again if they are running. But usually I just let the 8 stacks sit there and heal right before Undying rage is about to expire. This ability can really turn a fight, and late game allows you to tower dive like a champ. Nothing like killing someone right under their tower and walking away alive.

There is really only one thing that I can currently think of with Tryndamere. His ability to go through walls on demand. Spinning Slash lets you pass through smaller walls. This is a great way to save yourself from being ganked or going to gank someone. I use this little trick every game. Gets you places faster saves you and gets you kills.

Tryndamere is one of my favorite champions to play anymore. He is a simple champion to use but a mildly difficult one to master. Remembering to keep up your Bloodlust stacks at all times and when to use your ultimate is something that can only come with time and practice. Once you get those things down you will fall in love with this champion as I did and have a ton of fun with him.
If there are any questions please feel free to throw them my way in a PM. I will also have an Amumu and Ashe guide up in the near future so watch for those. If you liked the guide and found things that you can use or if this build worked for you go on and press that +rep button over there.