DT11 Temperature and Humidity Sensor Module is the best option to go for if you want to make a digital thermometer with Arduino/Microcontroller. This sensor can detect temperature and humidity simultaneously without any extra resistor and capacitor. Just need an Arduino. For tutorial in Bangla visit this link (আরডুইনোর মাধ্যমে মাপুন শীতের তীব্রতা)
DHT11 digital temperature and humidity sensor is a composite Sensor contain a calibrated digital signal output of the temperature and humidity. Application of a dedicated digital modules collection technology and the temperature and humidity sensing technology, to ensure that the product has high reliability and excellent long-term stability. The sensor includes a resistive sense of wet components and an NTC temperature measurement devices, and connected with a high-performance 8-bit microcontroller.