A breadboard is a convienent way to handle a circuit in development. The hole pattern differs with different breadboards - but we will focus on on the one supplied. Across the top and bottom the two rows pictured and labelled + & - are connected using metal strips horizontally - you usually hook up your power and ground to these and work from them. The top and bottom are not connected. Rows 1 - 30 are connected vertically - but again, the top and bottom halves are seperate. The central divider is there so that you can mount integrated circuit chips such as microprocessors.
Light Emitting Diode. A semiconductor diode that converts applied voltage to light and is used in lamps and digital displays. LEDs are not all the same. You must check the specs on what you are using BEFORE you put power to it - most of the time the longer leg of the LED is the signal and the shorter the ground - but if it isn't it could burn up. If you have to guess many LEDs are 1.7 V
Power source. This is your power source. Most electronics require 5V. The USB port supplies the 5 volts going to the arduino - and depending on the requirements may supply the LEDs, etc. as well. Generally the wire attached to power is red.
Resistor. Resistors basically convert electrical energy to heat. They are used to absorb extra energy and come in varying values. They have two leads with no polarity - IE they do not need to go in a specific direction. On a schematic diagram the value of the resistor will be written right next to the symbol. If you do not have the packaging a resistor came in you can identify it using charts such as this or by testing it with a multimeter. In this case we will be using a 100 Ω (ohm)
Ground. To be complete a circuit needs to be just that - a circuit. To complete it's loop it returns to ground. The ground wire is usually black.