I'm all for keeping the horizon low when you have an interesting sky - have a look at seventeenth century Dutch and Flemish landscapes for useful hints on this kind of composition - but unfortunately in this picture the clouds are a little too blown out and all that whiteness rather dominates the scene.
When I look at what's below I'm afraid that once again I'm left feeling a little frustrated. Because of where you have positioned the rocky outcrop and the buildings I find that I immediately want to see what's to the left or to the right of the frame and I can do neither. It would have helped to have turned a little in either direction to includes a little more of the sea and to achieve a less centre-weighted composition. But we have what we have, and what we have isn't without possibilities.
I'm in agreement with Ken Kruse about warming the foreground. Make a feathered selection and apply a warming filter for quick results - the wild flowers are an attractive part of the composition.
I agree with Tom Cooper with regard to cropping out most of the sky and trying to bring out some detail in the shadier portions of the picture.
And Nick Weal is right about the horizon.
And to the above I would add the following:
Crop out some of the left-hand side of the scene. Just below the smaller light house-type structure there are two walls running diagonally. I would crop to where the left-hand wall seems to disappear at the bottom. I would then make a rectangular selection at the top of the picture, feather it and then darken a little in levels (having done that you'll probably need to desaturate a little too). This will stop the top of the picture from 'floating away'.
Lastly, if you're thinking that this is a bit much for free software then try typing 'Photoshop CS2 free' into your search engine of choice. Adobe no longer want to support some of the older versions of Photoshop so they are giving them away! Free!
The picture has good possibilities and you knew what you wanted to capture. I think that it would help to pause for a moment to think about composition before releasing the shutter. Keep up the good work. Practice doesn't always make perfect, but it does make better.