Start with the jumper wires (J1-J25) if you don't have a double sided PCB. First add in those that are underneath ICs: J2, J3, J25. You may need to test-fit them with the IC sockets. Also you need to take special care with J11, J12, and J13 as those three go between pins of the IC1 socket. Alternativly, you can use longer cables and let them go around the socket. Put in the Resistors: R1, R6,R8,R9, then R2, R5, R4 ,R3, and, at last, R7. Now solder the resistors. Move on the the ceramic caps: C9, C6, C7, C14, C11, C12, C10, C13, C14 Solder. Resistor Arrays RN1, RN2. Solder. LED3, LED2, LED1: identify the negative terminal on the LEDs, its the shorter one, and the platic body of the LED is often flat on that side. Another way is to look inside the LED, the bigger part with the "cup" again is the negative terminal. LED1 has its neg. terminal pointing upwards (ie. towards the PIC, away from the power connector), LED2 has it on the right side, LED3 on the left side. Solder them. (Note that if you put the LEDs in wrong, nothing bad will happen, it just won't work :) Solder in the IC sockets: CON7, IC2, IC1, IC4, IC3. Before adding the IC5 socket, make sure you know what package your IC5 (74HCT154) comes in. DIP24 narrow (300mil) or wide(600mil). If you don't know and want to be prepared for both kinds, use four pieces with 12 pins each of the single row (machined contact) socket strips. (this is what I'm talking about: http://reichelt.de/inhalt.html?ARTIKEL=SPL%252020 ) Next add the single row pin headers for I2C (CON4), Reset (JP1), Priority Analog input headers (ANP1-ANP3), now the first sixteen Analog input headers (AN1-AN16), then the second row of sixteen (AN17-AN32) and finally the power supply pinheader (CON1) Move on to the electrolytic caps: first C8, then those for the serial port charge pump MAX232, C1, C2, C3, C4, C5. Make sure that you put them in the right way, as electrolytic caps are polarized (ie. they have a '+' and '-' terminal.) Electrolytic caps can explode when they are put in the wrong way. Note that C3 looks like it is wrong, because the '+' terminal goes to the board's GND, but this is indeed correct since the voltage on the '-' terminalis negative (below 0V). Continue with the (shrouded) dual row pinheaders: Digital Out Type B (CON6), Digital Out Type A (CON5), then move to the sixteen connectors for the keymatrix daughterboards, KEY1-KEY16 Next is the SUB-D 9pin male serial port connector, CON3. Note that you'll need a Null-modem serial cable to hook PHCC up to the computer. The 10MHz crystal oscillator, X1, should be installed next. And at last, add CON2, the other power supply connector. This one allows you to use a normal PC power supply since it uses the same type of connector as hard drives do.