Overclock questions.

[PH4NT0MBL4DE]

Ok in the futue I would like to overclock my pc. I have an i5 3570k and a gigabyte z77-dh3 motherboard and a radeon hd 7850. Can I overclock my pc. Now I don't think I can overclock my CPU just yet as I only have the stock intel cooler so probs best not to overclock until I get an after market cooler? But can I overclock my graphics card for now without doing my CPU?
Thanks.

 

[PH4NT0MBL4DE]

Ok that's great thanks. Is I left my CPU alone until I get a better cooler but overclock my 7850 as much as it will go will this cause any bottle neck issues or anything or will it be fine? Thanks.