This 42 n-experienced mech needs help

[lalink72]

1st off, I have an '85 c20 that I am trying to bring back to life after my 17 yr. old got a hold of it. Funny thing is I'm trying to do the mechanicing to put a 3rd vehicle on the road, so he can go to college(across town in the new vehicle!! Ha LOL
Anywho, The problem i have is i went to change the Valve Covers and gaskets and saw this on the driver side head. I DO NOT know much of any thing internal engine. Please any advice that could be given on how to fix this, CHEAPLEY AND QUICKLY!!

I appreciate it.