[ Diet & Fitness ] Open Question : Where can i buy a 3 month (for example) programme to help me improve my athlete build and muscle gain?

I am already slim built and have a 6 pack etc but i want to make my 6 pack tighter and more defined, my pecks bigger and mostly my arms bigger (whilst not forgetting my legs). Is there anywhere i can buy a reliable programme which i can follow to help improve my body? Thanks