I am kind of new to Star Trek: The Next Generation, and when I discovered Data and wondered: who is his creator? I haven't watched all the episodes and would like to know who created Data. Just a bonus, what is Data made of/or what is his programming?
Memory Alpha (Star Trek Wiki site) is your best resource for all things Star Trek.
MA's Data article tells you what you need:
Data was the fifth of six known androids designed by Dr. Noonian Soong. He was built on the planet Omicron Theta around 2336, after Lore was deactivated, and over the protests of Soong's wife Juliana. Soong claimed he built Data to perfect his design of his androids, and when Data was perfected, apply his improvements to Lore.
Bonus answers (but you should never post >1 question per post on SE, so I will only answer one):
He was composed of 24.6 kilograms of tripolymer composites, 11.8 kilograms of molybdenum-cobalt alloys and 1.3 kilograms of bioplast sheeting. (TNG: "The Most Toys") ... All told, he weighed approximately one hundred kilograms. (TNG: "Inheritance") Data's upper spinal support was a polyalloy designed to withstand extreme stress. His skull was composed of cortenide and duranium. (TNG: "The Chase")
Further details on Data and similar androids are on http://en.memory-alpha.org/wiki/Soong-type_android
Technically speaking, there were two creators
In TNG 'Datalore', we learn from Lore and some pretty strong evidence down on Omicron Theta that Data was created by Dr Noonien Soong. And in TNG 'Inheritance', we learn there was another:
JULIANA: Oh, Data, I was there, right at the beginning on Omicron Theta. I helped create you. Now look at you.
So, technically speaking, Data was created by two people: Dr Noonien Soong and Dr Juliana Tainer (then Soong).