How to share computer code?

I am writing a paper with my adviser.Some of the key contributions of our paper include:

1. A computer simulation model of an inventory system
2. A set of simulation experiments and results to validate the simulation model
3. An implementation of an inventory policy which we propose
4. Simulation results of our proposed inventory policy and inventory policies which are currently used in practice

We want to make our computer code freely available to others.The simulation model was written in the Java programming language so other researchers should be able to run the code on their own computers fairly easily.By sharing our computer code, we hope that other researchers will develop inventory policies which they can test using our simulation model.(Of course, it would be beneficial for us if they would do so and cite us in their paper!)

Question: What is a good way to go about sharing our computer code?

1. Where do I host the code?
2. Which software license should we "publish" the code under?
3. How do I make it easy for other people to run the code?