I really struggle with UV mapping at first, I couldn't get the hang of it at all and I think the best way to describe it is by quoting my Tutor "its like those annoying sock glove things , you put one toe in wrong and you spend half an hour trying to sort it out" Jared Taylor 26th Nov 2009. I say this because i spent hours at a time trying to layout UV maps where I had used the UV Projection Tool which does half the job and leaves the rest for you to arrange as neatly and coherently as possible. Towards the end UV mapping became easier but was still taking half a day to sort out. One of the things the video tutorials mentioned a lot was that the neater the UV map the easier it was to texture so I spent a lot of time just arranging the UV's. I also found he Mapping was really easy up until you extrude a face, move a vertex or just make 2 faces at right angles with each other.
Here you can see some of the UV Maps I made for my models
This is one of my simplest UV Maps of my back wall of my building.