The intel graphics will disable itself when u have the 7850 installed. Also the only thing u need probably beforehand is the drivers and some ocing software i recommend asus tweak to adjust the voltages and sapphire trixx to change the clocks since asus holds you at 1050 . Also get gpu z to monior ur temps and clocks.
Right now i have a his 7850 so you would get better temps than me but my clocks are 1150 for core and 1300 for memory clock
and i never go higher than 65 c .
That is a huge jump with stock i get 30 fps with bf3 maxed and when oced i get around 45 avg
Also don't be afraid to turn up the fan speed .
oh yeah for voltage im not a expert in this but i increased it to 1148 just so i get allitle bit more power to the card also it is good to increase the board power limit to max too.