Torah, the Five Books of Moses, was given to the Jewish People in a mass revelation at Mount Sinai. Torah contains the Ten Commandments, which in turn contain all 613 commandments to which Jewish people are obligated. In effect, we give our commitment to perform these commandments, and we do this for our own sake(rather than for the sake of the Creator, Who is not improved by our giving. The givers are the ones that benefit from the giving). To delve into this idea, of giving to a Supreme Being Who needs nothing from us, please see Rabbi Ezriel Tauber's book, Thoughts for a Jewish Heart: Rabbi Ezriel Tauber: Thoughts for a Jewish Heart
It takes the entire Jewish people as a unit to keep the 613 commandments because some are specific for men, some are specific for women, some are specific for Kohanim, and others for Levites. We see from this again how the Creator views the Jewish people as one. Again, it is important to understand this because if we have an entire body, every cell in the body is not the same as another...a cell of an eye is far different from a cell of a toenail. Yet, if we have a painful ingrown toenail, it affects the same body as the eye is in - every Jew is affected by every other Jew. We are in the same boat.
What is a commandment? A commandment is a way to connect to the Creator. When we fulfill a commandment what we are doing is the will of the Creator, we are doing something that we know is pleasing to the Creator because He has told us to do it.
Why would we want to please the Creator?
Imagine if one day, a man drove up to your door and gave you a check for a million dollars, free and clear. You would be a little shocked but happy, I would imagine. Now he drives away.
The next day, he comes again and gives you another check for a million dollars. He turns and goes away. Happily you go to the bank.
The third day, he comes again with another check. The chances are that before he turns to go away you might say something like "Wait a minute - would you like to come in for a cup of coffee? Is there anything I can do for you?"
This is the place of recognition for the good in our lives which generates the feeling of pleasure in doing the Creator's commandments. When we understand that we are maintained and are here at His Will, we become grateful.
This raises a whole subject of suffering, which can be accessed at:
Torah encompasses the Five Books of Moses, the Mishna, the Gemara, and the Writings. From these texts, we learn how to think, how to rise above our nature, and how best to serve the Creator. Recommended is
Artscroll Chumash with Rashi (English)
Fortunately there are many sources of Torah on the internet where classes can be listened to for free. Here is a list of some places to start: