Could someone please tell me the maximum dimensions for the header logo in 2.4? Thanks!
It depends on the theme you are using but, you can make the header logo any dimensions you want regardless of the theme you are using. The size of the container for the header/logo is defined with CSS. You can edit the CSS files in the theme you are using to customize the look and feel of your moodle installation. In Chrome or Firefox, you can right-click on the logo/header currently being used in your moodle installation and look for the class name (ie, <div class="page-header> or <a class="logo">) used then you can customize that with CSS using whatever height and width you want your logo to be.
For more info on working with themes: http://docs.moodle.org/dev/Themes
Thanks for your help!