Photos - your most powerful weapon

When putting together your own facebook page, website or external site listing how do you deal with photos? Does anyone use a professional photographer or specific software for editing? And how useful are photo sharing sites like flickr?

I'm particularly interested as I see photos as being probably the greatest tool you have in setting your own beautiful property apart from the nigh on 100 thousand others dotted about France. And we're busy working on the best way to showcase photos within our site with a focus on size & quality of image, number of photos & originality of presentation.

All thoughts are greatly appreciated.