I have built a reasonably large rockery recently and have also extended it and added other features since the initial build. Apologies that there are so many pictures here but you did ask for pictures and I do hope that they may be of some use, even if to only highlight the terrific amount of hard work involved!!
From the start of my build...
As well as your conventional rockery you could think about building other garden features using stone such as an old stone bridge for example..
Apologies but I did warn that there were a lot of pictures!
This is a cut and paste from another forum that I posted only this week and it may be of use? If not and I'm telling you how to suck eggs I apologise in advance...
"Rockeries are a great feature if a little out of fashion but they give a good opportunity to grow lots of different plants many of which can be good for wildlife. The holes and crevices in the rocks makes great hiding places for many animals, amphibians and insects also so I love them and built one myself fairly recently
There are a few tips worth considering when building a rockery such as...
Think carefully how the rocks should lay. Sounds easy but if you look at rocks in nature they don't all lie the same way, some will be horizontal where others will lay at a slightly different angle. Sometimes you get outcrops of a few rocks the maybe a single bigger rock for example.
It actually takes a long time with lots of putting rocks down and the gradually adjusting the position until it looks natural or even replacing it with a smaller or bigger rock or even a different shaped rock!
I know this sounds weird but it is true and you will find this out when you attempt it but it is quite satisfying when you find the right position for a certain rock especially if it's the sixth rock that you have tried in that position!! LOL
Before you build it look at other rock gardens and see what looks right and what doesn't work and why. You then need to look at natural rock formations before transferring all this knowledge into your own rock garden!"
Hope this is of interest and helps a little