Rince it, wrap it in a cloth and put it in the lower part of your fridge. You can keep it for up to a week.
How to prepare
There are many ways to eat cauliflower. You can eat it raw, dip it in mayonnaise or any dip actually. Or you can make a gratin with it. You can also bake it in the oven. You can make a soup. You can make some pickles. Tons of different ways, and all taste lovely, but my favourite is raw. :)
Note that the weight is an approximation.