** Carrara 6 and above
The Hair Tool is located in the main toolbar of Carrara
Assemble Room.
**Select this tab to jump in the Assemble Room
: 
To add hair to an object : simply drag the Hair Tool
and drop it on to this object in your scene.
To modify the Hair setting, select the Hair instance
attached to your object.
Now jump in the Model Room of Carrara.
**Select this tab to jump in the Model Room
: 
I use the following settings which is quite good :
Now, you may want to apply the shaders to the Hair.
Jump in the Texture room.
**Select this tab to jump in the Texture Room :
In this case, we will work with my "Real furs" shaders set for Carrara, available at renderosity.
Please note that you can choose any other fur or hair shader you want .
I assume that the set is already added to your browser.
Just select the "Real furs" folder in the Shaders Tab of the Browser.
Select a shader from the "Real furs" set.
Just drag this shader and drop it on to the Hair instance of the object.
Voila, that's done.
Just have a good rendering and enjoy!