Combining pictures professionally

Did anyone look at the back cover of Photoshop CS box? how would you make a picture that looks like that? I know the question in pretty vague, but look a the below:
example

I am pretty new at PS, so any help would be REALLY APPRECIATED. THANKS ALOT!

Well, among other things that appears to have been done by someone who had gotten straight A's in going for their degree in graphic design

Can you narrow this down a little bit?

This tutorial is not really what you are looking for, but it shows you the basic of what you need to know to do the stuff in those pictures. How to use mask, layers, gradients and pen/selecting tools.

http://www.tutorialized.com/tutorial/Dance-of-the-Dandelion/5545

Hope it was of some use!

I don't think that the answer to your question can be simple ... but in my opinion those pictures took some time to make and probably a lot of brushing / masking etc ... a sum of multiple techniques.
If you could easily do that you probably wouldn't be here asking it ... so the conclusion is: *nothing "cool" is easily done *

Ok, Ill do the blue one, just as an example, these sort of things are no where near as complicated as they look.
(Ill assume you have the basics of masking down pat, if the above link didn't help, goto www.worth1000.com and look at the tutorials there)
Start with a blue background, simple
Then add the picture of the model and mask out so only her head is visible
(now, the picture is very small, they look like leafs to me...)
Getting the image of a drop with leaves around it, put that on top of the layer of the model. Now mask the "drop and leaves" layer so only the ripples and leaves are visible. Use a soft brush for this to eliminate any hard edges that could ruin the flow of the image.
Use the color balance tool on each layer to increase the amount of blue tones in the image