Lacks information, the lack of farmatting makes it really annoying to read. Also so many wasted CDR. Your skill order is messed up, so are the masteries. The items... those seem more like you picked some random items.

Remember about the CDR reduction, it caps at 40% if im not mistaken, so... we are wasting some (a LOT) of it.

Some things:

Exhange ninja tabis for Berserker's Greaves you nee the as.
Buy the sprit visage more early.
Add more details, look at my build (click photo), i have a small ammount of info you know
Frozen Heart is actually a pretty creepy item for Warwick!
Buy more HP items maybe Atmog ( Atma's Impaler + Warmog's Armor)
Add more enchantment options
Don't spread out your masteries, go either 30 on a page or: 21-9 on the pages!
Add photos/pics and separations!
Create a intro that want me to read the whole build!
Check out a BB- coding guide if you don't know how to use them good!

For example:

spaaaaace!

I'm a creepy sick mongo who kill horses

space

some random info abut my pregnant squirrel on my back yard!

space

and here's you biuld info!!! (this is columns!)

I made this comment in 5 mins, it not hard to do columns and they help you alot!
They will also make you'r build better and more pleasent to read :)
Check out my build below for some examples on a more complicated build!