Trying to use arduino R3 output temp sensor readings on led breakout board.

First time doing something like this and doing coding.

What I am trying to do is, I want to use a temperature sensor with Uno R3 like the dallas DS18B20, LM35DZ etc sensors to measure the temperature then display the readings on a bar graph breakout kit (https://www.sparkfun.com/products/10936). The temp sensor will be used inside a computer where I expect the temperature to range from 26degC to say 36-40degC.

  1. problem is, I have no idea which sensor to use and 1 of the sensor (dallas ds18b20?) requires some soldering of resistor and some measurements to identify the correct resistor to be used. then some sites says connect the centre pin to pin 2 on the arduino board, others say pin 3.

  2. understanding the code. when I found some sample code that others use, I'm not sure whether which parts of the code I should include or whether they are there to explain to other users, the function of that line of code.

eg, from (MilesBurton.com)
19.// Start up the library
20.sensors.begin(); // IC Default 9 bit. If you have troubles consider upping it 12. Ups the delay giving the IC more time to process the temperature measurement
21.}

the part in bold, do I copy this part in as well when programming the arduino?

  1. Since the temperature range I wish to measure is rather small, how do I adjust the code/setup such that led bargraph can sufficiently display the full temperature range?

thanks all/