Thank you timethief, I have tested your method and works fine. It's almost what i was looking for. But, unfortunately, seems to be flash and doesn't work in some smartphones. And most of my readers use them to view the blog, sorry.
By other hand, justjennifer, thank you too for your help. Showing my pictures like your Greece gallery could be a solution. I have read the support doc on sending a single image from flickr but doesn't understand how to do it with a entire set. Could you explain me how? I would appreciate your excellent help.
As you see I'm new in WordPress and still learning how to use it. If any of you have a better idea to show the pictures, just let my know. Thanks in advance, again.