The combination I recommend for amateur usage:
- you need a good ball-head with a quick-release mechanism - I recommend the grip ballhead of Manfrotto, very easy to manipulate in all directions. Supports up to 5-6 kg (a pro-body and a serious tele-lens). I have modified the grip to be able to use it with my left hand, while reaching the buttons on the camera with my right hand (takes 10 minutes with the tools provided).
- the grip ball-head I am mentioning has a disadvantage: it cannot be used for panning. To do panning (panorama - stitching pictures together for instance), you need to be able to lock two axis so that you can move the camera in a single plane. You'll need another type of head.
The picture above gives a view of the total panorama combo: the grip ballhead mounted on a 300N Pano head (allowing to take successive picture at a constant angle (selectable)). It is of course necessary to lock the ballhead in a horizontal position using the integrated bubble level.
The better head I would recommend because of its accuracy is the hydrostatic 468MGRC2 head, reasonably priced.
More information to be found on http://www.manfrotto.com
There are other excellent manufacturers making tripods: one of the popular ones is Gitzo, there is also Velbon (a bit cheaper and lower end but good enough for many amateurs)