Adding text in header

[ChaoticKitty]

I have my website made and it is here:
http://www.treasureshaven.com
In the header there is a lot of blank space.
How can I add new lines of text below the line:
"YOUR BEST SOURCE FOR ROCKS, CRYSTALS AND BEADS"
Also, is it possible to add a seond picture or increase the size of the picture already in the header?
Thanks
DEAN

I got the following when I went to your url:

The server encountered an unexpected condition which prevented it from fulfilling the request.
The script had an error or it did not produce any output. If there was an error, you should be able to see it in the error log.