View topic - How to include Alt tags?

[Noodles]

Hi.

Some images on my site do not have Alt Tags defined. These would be the images on my sidebar and my logo so they show on every page and i'm wondering if it is significantly affecting SEO?

Also how would I define the tags? When I locate the specific image filenames in my files, I don't see any reference to ' alt="" ' which is what I would expect to see and which would allow me to define them. Any ideas?