I tried editing this photo using Gimp. I set a mask and changed the levels so I could get a selection on the church, I gave it more detail, then reverse selected the sky, I found it very difficult to change the sky, I couldn't get the brightness out of the cloud. Then when I looked at the image there was a horrible noticeable line around the church, I always got that using the laso tool, but how do I prevent it. do I have to change the way the image gets loaded.
Duplicate the layer>sample the sky colour>add a new layer inbetween the bacground layer and the background copy>fill it with the blue you just sampled>delete the sky on the top layer
For the clouds i added them onto the blue layer with a "cloud" brush tool.
Kanikula that was very nicely done. This was also done with CS3 and is a very easy way to correct blown out clouds doing this. Duplicate and uncheck the original layer. Next add a selective color layer and choose whites and with absolute checked slide the cyan slider to the right until you get the desired sky color. On photos that have whites in other areas you don't want affected you can use a selection tool such as magic wand to adjust a specific area.