quick hosted site

Hi,

I'd like a "very cool-lookin' site" since it seems to be what the niche market I'll be getting into would demand -- but I've heard that SEO works on text and links and that graphics can compromise SEO. Is that true? In what ways? And how does the picture change, if at all, when Drupal enters the picture, especially with regards to a "quick hosted site" service such as Drupal Garden or Pagebuild?? I know this is a newbie question, so please forgive since I'm still finding my footing!

TIA