I'm covering everything, so it's definitely all been covered IYSWIM!
Really don't go for newspaper. It's too slippy and will lead to splayed legs (a potentially serious, but completely avoidable and, if you know what you're doing, fixable deformity . . . but it's better not to get into that situation in the first place). Kitchen roll will work better. It's best not to give them any other bedding for the first few weeks - they can mistake it for food (I know, not the brightest creatures).
In terms of the cardboard box, it's going to end up filthy very quickly, and I would be petrified of it catching fire. What would be better is a plastic storage box, with a mesh cover (some of that hard chicken wire stuff is good) over the top, to stop them jumping out, which they will be capable of alarmingly quickly, and allow ventilation. If the cat's a worry, then put something heavy (a brick!) on it to weigh it down. Of course, they will need more space, still indoors, after a couple of weeks, so you need to think what you're going to do about that.
You'll also need chick crumbs, and they will have to be fed those for the first 6-8 weeks, then switched to growers pellets until 16-18 weeks old, and then on to layers pellets permanently. A lot of people recommend scattering chick crumbs over an egg tray (or the egg bit of an egg box, if you're going small scale) as it gives them more to find. However, this will need replacing daily for obvious reasons.
They'll also need a proper waterer. It needs to be one of the upright ones, with the water 'tray' bit not so deep that they can climb in (it leads to drowning / hypothermia, again, not the brightest creatures). Ones intended for aviary birds are good, such as npi.petplanet.co.uk/shop_dev/assets/new_product_images/vital/55318.jpg and there's nothing to stop you continuing to use one that size as they grow older.
You'll need a proper heat lamp, with a way to raise and lower it. If they cluster together under the heat lamp, they're too cold, so it needs to be lowered. Spread out against the edges means they're too hot and it needs to be raised. An even distribution of chicks means they're just right. They'll need supplementary heat overnight right up until they're properly feathered out.
Oh - and if they're not sex-linked (i.e. able to be sexed at hatching, based on the colour of the feathers) then a strong stomach / capable farmer friend to dispatch the cockerels!