Introducing Integrated Circuits

In PC/CP120 labs we'll walk you through wiring a simple gate circuit using one specific integrated circuit (IC) the 7400 chip. It's a good introduction to some of the more complex logic chips that you'll be using later in the lab.

The 7400 integrated circuits are historically important as it is the first widespread family of IC logic. It was used to build the mini and mainframe computers of the sixties and seventies.
Need more info about 7400 see wikipedia

IC pin numbering and orientation

Locate 7400 chip/IC in your lab kit NAND chip . This chip is written on it SN74LS00N. The LS tells you that it is a low power Schottky chip. The manufacturer embed 74LS00 and other part numbers.

This is a Dual-Inline Package (DIP), referring to the chip’s two rows of pins. Notice that this chip has fourteen pins. If you want to use an IC chip, then you will always need to know the pinout. That's electrical engineering lingo for describing the way the pins are connected to the internal circuitry of the chip. You need to know where the power supply is connected and where the gate inputs and outputs are connected.

Where and how to know the IC pinout? you will need to look into the IC datasheet. The manufacturer provides you with the IC datasheet. See 7400 datasheet for example.
For 74-series IC data sheet index see this link

Here's a picture of the 7400 chip in a circuit board:

NAND on board

and here's the pinout for a 7400 chip:

NAND pin description

How do you know which pin is "pin 1" on the IC? You will find either a circle marking the first pin or a semicircle marking the top of chip. The pins on an N-pin DIP are numbered as shown :

Dual-Inline Package Chip .