First picture: hooded 4 pin square plug is for the neutral safety switch/back up lights that go to the transmission. If you have a manual transmission, the NSS lights are jumpered on the mate to that plug.
The plug with green wire is for Air Conditioning.
Single female plug with blue/red wire is for the PRDNL lamp (only used if automatic transmission).
flat 3 prong plug is for your engine gauge feed harness: coil, oil, water. Some later pictures show that harness, and one shows an extension, missing the oil pressure line, IIRC.