To insert an image in a module page or in a forum post:
Make sure you are using the RTF editor, rather than the plain text editor. (The RTF editor has the toolbar at the top.)
Click the picture icon in the editing bar.
Click Browse Server.
Click the Upload button in the upper left corner of the window.
Click Browse and locate the image file on your system.
Click the Upload button next to the Browse button. This uploads the file into a directory that is specifically yours.
Select that file in the directory.
Click the Send to FCKEditor button.
Click OK. This inserts the image wherever you had the cursor set in the editor window.
Note: If you upload a revised version of the image that has the same name, the Upload page will add a number to the name of the new file you upload. If you want to just replace the old image, then before uploading the revision, select the old image and click Delete. The newly uploaded file will keep its name.