Pictures in Blog Posts

I am trying to “embed” pictures in my blog posts. The problem I am having is twofold:

1) the border that surrounds the pictures and encapsulates the caption is getting distorted. For some reason the pictures that are in profile format have an off center border and caption placement. Furthermore, if there is more than one picture inserted in succession, the second photo’s border is somehow stretched up behind and off center of the previous picture

2) regardless of the resizing efforts using wordpress media editor, the picture is expanded to fit the original size of the picture. For instance, if I tell it to make it a thumbnail size (predetermined size by wordpress) or if I use advanced settings to resize the picture, the picture in the post stays the same time but becomes distorted as if it was stretched to fit a predetermined size by the theme.