How to have a common library between projects

[Satal Keto]

I am creating a project, which will eventually contain several applications each written in Java. There will be a number of classes which will be common between each of the applications, so I was thinking that I should create a common library that contains these classes, the problem is I'm not certain how I would go about doing this.
I have done some Googling, but found no results which helped me, so I was hoping that someone could help me and give me a brief explanation on how to do this if its simple, but if its a bit more complex then a link to some good resources would be appreciated so I can do some reading into it.

Thanks for any help/advice in advance.

Satal