As someone said earlier, lard is the name given to the rendered fat. Suet or back fat is what you want to ask the butcher for.

There are a couple of ways to render the fat here: http://www.thenourishinggourmet.com...ender-lard.html

It looks like back fat in the photo. Nothing wrong with that (I often use it), but suet from around the kidneys is better, IMO, because it has a less "porky" flavour.

I do mine at a slightly lower temperature 140-145ºC. I don't really time it, but keep draining the rendered fat every now and then. I whack the heat up at the end to make crispy, fatty bits of goodness that don't seem to last very long at all!