well after you've uploaded the pcitures onto your pb account then there will be 3 lines underneath the thumbnail, they'll be the url, image tag and hyperlink (i think thats right anyway). what you wana do is copy the image one, you'll know it's the image tag one because at the start it'll have "[img]" and then at the end it'll have "[/img]". once you've copied that then just put it into your post and it'll appear in your post
Hope that helps mate