picture in the post or page

Hi, I was wondering if there is a way to set pictures in a post small but when one clicks on them, they would appear as full sized pictures? I like to have a post with small pictures, but my readers are complaining that they would like to see full pictures when they click on them. Is there a way to make it work? Thank you, Beata beata.swist@gmail.com www.beataintheworld.com