As Davideo says, start with the 4 sockets on the innermost bit of the card, and work out to the edge.
For utter avoidance of any {bleep}-up potential, if you look at the top picture on
http://amiga.resource.cx/photos/a2091There's 16 ram chips on the left of that card. You need to install chips in banks of 4, and they line up vertically from the rightmost sockets.
I know that's labouring the point, but wanted to make sure there was no ambiguity!
