Can anyone axplain this to me.... Pleeease...
I'd like to make a big water surface: a river or even the ocean... a big shining surface...
Is it possible?

Try this:
1. Default colours (D)
2. New layer > Filter > Render > Clouds. Set layer opacity to 40%
3. Filter > Blur > Gaussian blur @ 4 px. Set blend method to Overlay
4. Image > Adjustment > Equalize
5. New fill layer > Solid Colour Turquoise > Overlay

I found this tip in one of those 'creative PS' magazines. There are also many free trial plug-ins which you have to pay for after 30 days. Google the relevant entry.

Hope this helps