Help with customizing wordpress categories

I have a web running WP script, here.
I want the categories to have a permlink like:
.com/news
Can someone help me getting that?

Or if i want my categories list to appear on a navigation bar at the top, does that depend upon the theme or I can customize that too? If so, kindly tell me how i may customize it!

Thanks

 

http://codex.wordpress.org/Using_Permalinks..

The position of the category navigation depends on the theme you are using..

 

What you need to do is to customize the Apperiance Section and add columns to the position you want.

Hope that helps!