All components sit on the component side, with their leads poking through to the solder side. The board is then soldered from the solder side.
Don't get it backward because the board won't work, unless it is transported to a parallel universe.
The above diagram shows a side view of an LED and the part silkscreen legend. The shorter lead of the LED is the cathode, which goes in the square hole.
The cathode is marked with a band nearer to the cathode end (see above diagram).
If a capacitor is non-polarized (e.g., any value 0.1 uF or less), don't worry if the board has a square pad and a round pad. It doesn't matter how the capacitor is installed.
The above diagram shows how to count pins on a DIP (dual in-line package). Find the notch, and then pin 1 is in the lower left corner beneath it. The pin numbering proceeds counter-clockwise from pin 1.
DIP sockets have a notch like the notch seen on the chips themselves.
The above diagram shows two sample 8--pin resistor packs. The left-hand pack has the ``band style'' marking; the right-hand pack has the ``dot style'' marking. In either case, the marking indicates pin one of the resistor pack, which goes in the square hole.
The above diagram shows the 6811 socket, with its chamfered (or truncated) corner in the upper left. The 6811 itself has a matching chamfer in its upper left corner (the 6811's pin 1 is indicated with a dot).
It is imperative to install the PLCC socket with its chamfered corner directly above the chamfered corner of the silkscreen legend. This is because once the socket is soldered down, the 6811 only fits into it one way, so the socket must be soldered correctly.
6811 Chip Pin Numbering
Looking down at the 6811, the numbering of its pins proceed counter-clockwise from the pin 1 dot. E.g., pin 2 is immediately to the left of pin 1, and pin 52, the highest-numbered pin, is immediately to pin 1's right (see diagram above).
6811 PLCC Socket Pin Numbering
There is a non-obvious translation from the simple numeric progression of the 6811 pin numbering to how the pins appear at the PLCC socket leads. The above diagram shows the pin numbering, looking up at the PLCC socket from the bottom of the PC board. In other words, the diagram shows the pin numbering assuming the board is turned upside down, and the viewer down at it.
A recommended method is to repeatedly score the header at the desired break point, using an X-acto or matte knife to gradually dig deeper and deeper into the cut line. Score the header several times on both sides of the groove between two socket pins until the header can be gently snapped by hand.
If done patiently, this process ensures clean breaks between the header sockets.