Getting images to line up next to each other can be tricky. I think most of us have felt that pain before. Generally you want to make sue there is enough room for both images and their right hand margins when you’re inserting them into a page/post. You can also insert a gallery. That will cause them to line up for you.
Galleries are added via a “shortcode” which you can edit. Once you’ve inserted your gallery, click on the text tab and you’ll see something that looks like this:
[gallery ids="9,28,34,75"]
You can add a size to that to replace the default thumbnail one. The options there are explained in more detail at http://codex.wordpress.org/Gallery_Shortcode . It would look something like this:
[gallery ids="9,28,34,75" size="medium"]
To use the medium image size that WordPress auto-creates for each image.
If you’re coming from print, it can feel very frustrating. As the screen size changes, this changes even more as things really start to move around.
From my own experiences, I generally make my images either the full width of the content area I’m working in, or half width. I’ve found those tend to work better across screen sizes.
Bill