Refrigerator + Arduino + HELP = thanks

Well , First of all let me indroduce myself , mi name is Matías im 18 years old and i'm from Chile. I'm a engineering student (well i'm in first year , but i feel like Tony Stark right now ajajajaj) and i'm interested in electronics. So I wanted to start a proyect and the idea is to turn an old fashioned (not so old arround 8 years old) home refrigerator to an "Intelligent One" I'm pretending to use Arduino to control temperatures, compressor ON/OFF , and why not a LCD Screen. What I've thinked so far is this: My DS18B20 Thermomether will meassure internal temperature also I want One in the outside to get environment Temps . Also I want my fridge to strictly work between X and Y Celsius degrees. I've thinked that a relay conected to de compressor that allows to turn it ON when Temperature goes over Y degrees and turn OFF when Temperature goes lower than X degrees. Also I wan't to check periodically the temperature. About 1 check every 5 minutes and plot that data . I think that a 4D touchscreen could be atached to control certain parameters like temperature Range and see Temperature's plot Live(Internal and Environment). Also I have a RTC to log the temperature with the time it was taken for better control. Also attach a magnetic sensor to the door , so if i let it open for more than 30 sec an alarm will tell that the door is open and a sms will do it also. also if the compressor works for more than 2 hours consecutive a sms will said that something is not working

Well this is an Introduction to the project , now i'm working with RTC and temperatures and i'll be posting issues and troubles here . Thanks a lot Best Regards Matías .

Well i have a question , I need to get Temperatures each 5 minutes but i dont want to put a delay() what can I do ??? please help i'm a begginer with arduino. How you can Call the function without having to freeze de program for 5 minutes ? Thanks

kcsss:
Well i have a question , I need to get Temperatures each 5 minutes but i dont want to put a delay() what can I do ??? please help i’m a begginer with arduino.
How you can Call the function without having to freeze de program for 5 minutes ?
Thanks

See the BlinkWithoutDelay example.