DOCBOOK-APPS: Need some sample stylesheets to start out with.

Hi,
 I'm new to docbook. I just finished writing my first book byt cutting 
and pasting the sgml
souce from the Docbook book from O'reilly.

I use dbhtml to process my xml document.

I'm trying  to  create some cutomized look and feel.

For e.g in the html output that is generated, I would like the following:

A custom logo that is displayed on the header of each page
turning on/off navigation header/trailer
Having gifs images that can be used inline instead of the prev, next, 
home , up link etc
being able to set the foreground/background color etc for the pages  

I understand that some of the above is done by modifying the dtd and 
others can be done
by including my own style-sheet. I have no idea  how this can be done.

Are there some sample layouts out there that I can modify to get to what 
I want?

thanks a lot
Sudhir