I am considering getting me a Graphics Tablet. But I have no idea about these at all... :/

I am basically looking for an input device, a replacement for my mouse, when drawing and coloring, mostly in Photoshop, Gimp and other graphics software.

But I don't know anyone who has used a tablet, so I don't know what to get or what features to look for in a tablet.

So does anyone have any idea on Graphics Tablets? What features they come with, If they're available in IDB and how much they cost.