You can have mine if you want it.... We bought a house with a pond in it, we have pet frogs. If we don't get frogspawn this spring I'm filling it in. I can't imagine it would be tricky to build a pond, ours is a bucket type thing, about 1.5-2 metres across. I have delved a bit but can't finda bottom to the bucket and I've gone down to just under a metre. I don't know, but I imagine its a simple dig a hole and put a liner in and let the rain water fill the pond. Do you plan to stock it with anything? Or wait to see what decides to live there?
It's not difficult, but there's a lot of digging involved. I've watched my green-fingered father make several ponds.
Are you thinking of getting a rigid pond liner, or doing it yourself with the plasticy stuff?
Basically the theory's the same - dig a hole bing enough to fit you liner. Check all nasty sharp stones are out of the hole. (I'd put down a layer of sand, if it were me, just to cushion it) Then you put the liner in. I'm not exactly sure how you make the non-rigid ones waterproof.
You fill it up with the hose, then put plants in it (in pots which are weighted to sit on the bottom) and put decorative stuff around the edge to make it look pretty.