[Alan]

Ollie, when you're writing a post, at the bottom of the page there is a button that says 'Manage Attachments'. Click on this and you can then brows to your image in the some way as you do for the gallery. When the file name's in the box, click the add button on the far right of this and this will add your image to the thread. You don't have to make thumbnails or resize images. It does it for you.