How Much Carbs / fats to consume for a low carb diet ?

For a low carb diet, what would be a suitable ammount of fat/carb to consume in a day? Would something like this be ok:

100% of your RDA of fat (70g I think) as usual
&
10% of your RDA of carbs

be ok?

Also how long is it before you notice any difference in say weight?

I am aiming to shed about 1/2 a stone, but work harder and perhaps put that on again but in muscle.

I figured that loosing weight this way meant I still have the nessacery proteins
that I need for building my muscles as I do extra physical work.

Does this sound ok?

Also how many calories would you recommend to eat in a day? Normal RDA or cut it down?

1 other thing, does anyone have any nutrition lists? For example I have a roast chicken, but ive no idea how much fat is in a chicken leg.