To re-order a category, you just move all the forums in it to where you want it to be. The categories move with the forums
Click on "Edit Forums", then "Reorder Forums" to re-order forums.
To upload an image, if you're on the fixed or variable (paid) plans, you can use the file hosting we provide (click on "View File Hosting" in your admin centre). If you're on the free plan, you'll need some web space which allows hotlinking. Have a look at netfirms.com or brinkster.com . Then upload your image there, and click on "Easy Customization" in your admin centre, and enter the URL to it (your host should give you that), in the "background" box.