To clear cache, delete everything inside the folder “cache” in Public_html/var
Go to Admin area of the site
System–> Configuration –> Design –> Select Header tab
You can see relative image path, Image alt text and Welcome text there.
To use relative image path, put the logo first in the image folder inside skin/frontend/themefolder
Go to Admin Area
–>System –>Design –> Add Design Change
Select the Design you want from Drop Down list for Custom Design