dont know if this has already been covered in recent post but bare with me please.

i have a d15b7 and apparently oil is leaking into the sparkplugs. mainly the sparkplug on the far right. and im also guessing this is why my maintance light is turning on after a few minutes of driving as well as a couple oil drop leakage. noob at really messin with the internals of the motor so where can i get a cheap gasket due to being in school, what parts do i need or should get in addition to all that replacing, and maybe a how-to to replacing the gasket? thanks guys