2D Grid puzzle game

Hi i’m about to start making a 2D puzzle game similar to the pipes game (http://www.blogcdn.com/www.joystiq.com/media/2008/06/pipe_mania_windows_0001.png)

And i want to know some recommendations about how to approach this, some techniques , tutorials, ideas, opinions. I want to build and edit the maps as fast , nice and flexible as possible.

What do you recommend or what direction do you think i must take?

Unity answers is for specific technical questions. Better use the forums and discuss this with people there.