Need simple modification how-to for garland

no matter what theme i try, i constantly get back to garland.
(see http://www.1up-seo.com)

What i need is a mod or the instruction how i can head a background to the blog-entries, so the blog-entries and everything doesn't "run into each other" (if you know what i mean).

So..where the titles are ...example

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Tue, 07/24/2007 - 10:42 — admin

for a blog entry...i want this (as in many other themes) with a background-bar so every blog-header/title stands out more from the background.

Regards,

Georg