In simple words, open science is about sharing your research material with the world. This practice helps a lot both personally, and for the broader community.
Personally, it will teach you how to organize and structure your data in a good format so that it is easily accessible to the community. Sharing code and dataset, also means overtime you will push yourself to code better and prepare your datasets more scientifically.
For the community, by open sourcing you are encouraging reproducible research. You are providing open data for new researchers to explore your domain, and you are creating reference points for performance comparison of future methods.
I have tried to make all the academic datasets and codebases that I have developed over the years public. This section of my website collects pointers to all these resources. You can find them categorized in the following manner.