A well played Lanewick will be a strong in all phases of the game and not just in the laning phase. While in laning phase, WW's passive and Q combine together to give amazing sustain so that you can stay in the lane for ever...
Even when your team begins to group up and push lanes WW still comes in handy with the tankyness and his insane Ulti that will suppress some poor soul for 1.7seconds. When your team reaches the turret, his W will bring it down quickly, and he can even (well almost) solo a tower.

Magic and Armour pen are there to help our your R as well as your basic attacks
Dodge, helps with the defense
Cooldown - spam your Q more as well as bringing your R down so that you can get more kills more quickly

If you are doing well I tend to go for this build, as it helps with auto attacking and beefs up your R to do A LOT of damage. The magic pen boots will benefit your R as it deals your AD scaled damage as magic damage. Because of your high attack speed, those critical strikes will help you deal out more damage when you finish suppressing your enemy. The Bloodthirster is there as it gives the most AD if you farm up 40 creeps as well as giving you crazy life steal with your passive.

If I (for some reason) are not doing the well during early mid/game or our team is lacking a tank I go for the Atmogs build as it gives you still AD as well as armour and HP. This item build will allow you to initiate team fights with your R, providing that your team is there to back you up.
Tanky Build

Take your first point in your Q, then in E and the third in W.
After that level up your Q when ever and your R when ever it can be.
E & W should be leveled up last.

Ignite - always gets the last little bit of HP left that always seems to happen to an enemy


Use this right after you ulti them and it will allow you to autoattack them a lot, and get their health below 50% so you can go on a movement spree.

Grab cloth Armour, 3 mana potion and a health pot and head towards either the top or bottom lane.
When the creeps reach you, hang back trying to only last hit them whenever you can and using your Q to harass the enemy champions. WW is very mana hungry so try to grab the blue buff when you can and make sure that you have enough mana before committing to an attack on the enemy.
When you reach lvl 6, head back, grab your boots and Madred's Razor and head to the red buff, take it and move a lane(pref. mid) and get ready to gank it. As soon as they over extend use your ulti, wait 1.5 seconds, use exhaust and ignite and chase them down with your Q and auto attacks. Doing this with a team mate almost always results in a kill.
If you then head back to your lane, repeat the above steps when your enemy over extends

By now you should have built your Madred's BloodRazor and starting to push lanes. This is where you can really grab some kills with WW.
WW's E has massive range, so be sure to always have it turned on. After team fights, people with low health tend to go back into the jungle to B, well with WW you can see exactly where they are and hunt them down.
As your team moves up to one of the towers, use your E and it will be gone in only a few seconds

Keep building up your items when ever you have enough gold and ulti'ing some poor champions