Many questions answered here:
http://www.texasphotoforum.com/forum/faq.php
To add photos as Attachments to a post, look right under the "Reply Box" where you type your post in another section entitled "Additional Options." Therein, you will see a specific command set for uploading the photos from your own computer:
Valid file extensions: bmp doc gif jpe jpeg jpg pdf png psd txt zip
JPEG file size limit: 293.0 KB
Pixel size limit: 900x900 (800x600 is better)
Just use a Photo Editor to resize your photos to conform to the above requirements, and your photos will appear in your post.