Ther is a nice wee programme called Machinists Mate, you can download the demo and see if you like it. I still use it quite a bit and it gives you a ballpark figure to aim for, you can then tweak your feeds and speeds to suit your particular machine. All you have to do is enter the mills Dia, the material, the material of the cutter, whether its an endmill or facemill or whatever and how many flutes (tips) and it will gve you feeds and speeds. Either that or you can look up your cutter manufacturers website and they should give you info on chipload per tooth etc.
Hood