The list is partly my own, borrowing some from Tom Igoes Making Things Talk (a book I highly recommend) and a thread over at the Arduino forum I started.
Bread boards: I thought I would only need one or two. By experience I know better and if you're like me, working on multiple projects, it's nice to have a few. It saves you the trouble of deconstructing and reconstructing half baked projects.
Jumper wire: For the breadboard. There are alot of different models. I've used solid core wires that were labeled for use with bread boards. I don't really care for them, however I don't have any other recommendations.
DC adaptor: The Arduino uses a 2.1 mm center positive plug. However since you never know what you might need it's quite good to get one with interchangeable plugs in different sizes. Preferably with variable voltage aswell.
- DC 2.1 mm jack
Useful when using a separate power source to your projects.
- DC 2.1 mm plug
Useful when powering from battery.
- 9V battery connector
Same reason as above but for the other end.
- Headers female and male.
Alot of different uses. Especially when it comes to connecting wires to a breadboard.
- 100 Ohm
- 220 Ohm
- 470 Ohm
- 1 k Ohm
- 4.7 k Ohm
- 10 k Ohm
- 22 k Ohm
- 100 k Ohm
- 1 M Ohm
- CdS resistor: 2-5 k Ohm
Works as a light sensor if you hook it up to your micro controller of choice.
- NTC resistor: 4700 Ohm
A.K.A. thermistor, like the above but senses heat instead.
- Potentiometer: 10 k Ohm
Extremely useful when working with micro controllers.
- 0.1 uF ceramic (sometimes labled as 100 nF)
- 1 uF electrolyte
- 47 uF electrolyte
- 10 uF electrolyte
- 100 uF electrolyte
- H-bridge: L293D
Useful for controlling DC motors and stepper motors. Allows you to switch polarity of the outputs.
- Darlington array: ULN2003
Useful for controlling bigger loads such as stepper motors and LED-strips.
These are pretty much generic transistors that my supplier had in stock. If you can't find a specific transistor, just swap it out for one with similar specs.
- 2N2222A TO-92 NPN 40V 800mA 300MHz
- BC547B TO-92 NPN 45V 0.1A
- BC557B TO-92 PNP 50V 0.1A
- TIP120 TO-220 NPN Darlington 60V 5A
- IRF540 TO-220 N-ch MOSFET 100V 28A
- 2N3906 TO-92 PNP 40V 200mA
- Red 5 mm dim
The most basic of LEDs.
- Red 5 mm clear super bright
Together with the green and blue below it's what you need to do color mixing.
- Green 5 mm clear super bright
- Blue 5 mm clear super bright
- 1N4004 DO-41 400V 1A
- Zener BZX55C3V3 DO-35 3.3V
- LM317T TO-220
Variable voltage regulator, with two resistors you can get output voltages from 1.2 V to 37 V.