Nilla, it's so easy to post a photo, and we want to see your fabrics! If you glance down to the bottom of the page, you'll see three blue tabs -- 'Post Quick Reply', 'Go Advanced', and 'Cancel'. Choose 'Go Advanced'. Then, once you're on the 'Go Advanced' page, scroll down, past the 'Submit Reply' and 'Preview Post' blue tabs, and you'll be in the 'Additional Options' section. Scroll down a little more, and you'll see the blue 'Manage Attachments' tab.
You click on the 'Manage Attachments' tab, and that will bring up an additional box. Just near the top, there is a gray tab that says 'Browse'. When you click on 'Browse', it should bring up your own personal picture files. You choose the one you want, then click on the blue 'Upload' tab to the right. There's a few seconds wait, then the information for the picture you've chosen will appear just below, in a new section called 'Current Attachments'.
Depending on the type of photo editing software you use, you may have the option to re-size your photos before adding them to your post (mine come out huge unless I re-size). It's really easy as pie (or really, much easier than pie, as I never found pie particularly easy).