The built in UER upload doesn't work so hot. There used to be a cool "AV Uploader" that automagically resized all your images, but that went by way of the Dodo bird when the plug was pulled on Flash. To use the existing image upload you'd have to use a 3rd party site to resize your images. I use http://www.imageop...et/Pages/Home.aspx
But there is a better way.... Check out this link in the rookie forum: https://www.uer.ca...d=1&threadid=60002
Some items are dated, and may/may not work or no longer apply. I personally use item 7.3 (Flickr) from the above link. It's free (up to 1000 images), and easy. You can also reply to the above linked thread as a way to practice with a single image - just keep using the "modify" button at the top of your post until you get it right. You could also check out a thread where someone posted pics, and hit the "reply with quote". You don't need to actually reply, but in seeing the window that pops up it shows how someone linked their images.
I look forward to seeing what you have to share!