Televisions and video recorders made for the UK will not work in Australia, because the frequency of the sound signal differs between the two countries - you might be able to tune into a TV station and see a picture, but you won't be able to hear the sound. However, Australian videos will work on a UK player, and so it might be worthwhile taking the video and TV so the children can watch videos without interrupting you!
Also, you should normally forget about taking the fridge (too small - and will probably not be sufficiently durable to cope with the heat), wardrobes (most houses have built in robes), and the cooker (provided with most homes).
Note that Australia works on the same electrical voltage and frequency as the UK so you won't need to adjust the settings on your electrical goods - although you will have to change the plugs or buy lots of adapters!