As stated beforehand should probably find a less distressing colour then light blue in the creeping/jungling section. The guide covers the basics but is missing some important details such as skills and its usage but I suppose these sections are under-construction as foretold by the last paragraph so I'll just review what is there.

Item Build

I'd firstly really advice getting Atma's Impaler after Warmog's Armor it is the single most cost efficient item in the game right now for the stats it offers it is abundantly cheap, the attack damage given is basically equal to that of B. F. Sword except it continues scaling higher.

You should include 3x Doran's Blade option as an alternative to Wriggles Lantern if the enemy team composition is unbalanced or if that the enemy APs happen to be a more formidable threat then triple Doran's will provide more use. Also, Last Whisper is worth a note if some one who is a threat to your team is stacking armor your damage will become futile thus Last Whisper becomes a productive answer while remaining relatively cheaper then Black Cleaver.

Masteries

I'd question bothering getting Deadliness and Lethality since you are the tank and likely initiator of your team thus to put 4 points towards critical strikes is a rather costy for a champion with no scaling mechanics interacting with the stat like Tryndamere, however this guide does seem more directed towards a "offense" style so I'll let it slide but I will say that if you are going towards said style then it would be best for you remaining points to go into utility to pick up Expanded Mind , Swiftness and perhaps Runic Affinity if you wish. Or, just dumping points into Hardiness and Durability for that added beefiness if that's what your looking for.

Runes

Greater Quintessence of Attack Damage are superior then Greater Quint of Desolation due to the ratios given by the two. I personally don't find that Lee Sin really needs any extra attack speed due to his passive Flurry.

Summoner Spells

You should include the Smite+ Exhaust combo which has become increasingly popular since the snare helps ganking a lot and makes you an even better duelist in the jungle then you already are.