As above really, you dont need anything. A grey cloudy day is perfect.
Put camera on a decent tripod and do a long exposure.
If you don't want some kind of light box for more shadow control then get a big cardboard box and cut out 2 big window on the sides. Glue/tape low weight white paper over the window. Put higher grade white paper in the inside of the box, preferably buy a sheet of think paper/think card that is large enough such that the bottom and back can be covered in a single piece without a join, just have the cardboard slowly curve at the back.
Put 2 powerful desklamps pointed straight at each of the windows. If you really want to spend you can buy a couple of 500-750w flood lights dirt cheap from wickes and point one at each window.
Try to over expose the photo as much as possible without overexposing the subject. Ideally you want the white background e to end up so overexposed it clips to pure white. this is obviously much easier with a dark object. In post processing bring the shadows down so the object is properly exposed and push the highlights and whites up
further until the background is clipped to white Crop, color correct and move on.
Ideally you want the out of camera photos to be more or less good enough - with trial and error you will get it that way. Then you don't have to spend too long at the computer.
For light/white objects you likely want to use a darker setup without the white background, something like black or light blue. You can buy card in a few color and slot into the cardboard light box.
Kind of like this:
http://www.wikihow.com/Create-a-Lightbox-from-a-Cardboard-Box
But preferably the white card for the base and back gets curved like this:
http://digital-photography-school.com/how-to-make-a-inexpensive-light-tent/
