If you have a Flickr account you can post them on here by selecting the photo, click on 'share' at the top of the photo, select the BB Code button at the bottom, select the size you require and copy the info in the window.
In your thread click on the 'Insert Image' icon which will open a new window and paste what was copied into the link. Press 'OK' and the photo will be in your post.
I assume it's a similar method used by the other photo sharing sites like Photobucket etc, it just depends on what you have. Hope this helps, there are other threads showing the method with photos to illustrate the method if you have a search for them. Good luck.