I can't see the main navigation sidebox on your site and so can't diagnose the problem. One possibility would be that you have unbroken text in there that forces the box to overflow the width that you have given it.
You also have a login sidebox that is overflowing its allocated width. To deal with this you would have to edit the size attributes in the code that generates the input fields for the email address and password.
Also your thumbnail image files are way to big. They'e detailed files and you want them to look good, but you would get better-looking and faster loading images if you used a specialist tool to reduce the image sizes rather than trusting your users' browsers to do the job.



