The process of making a decision about your life with help of the Holy Spirit is called "discernment." It is the process of discovering God's will for you.
In this process you deal with two persons: you and God. During the process, you will get to know both better. As you begin, remember that both you and God ultimately desire the same thing -- your happiness. You want to make a decision about your life that will bring you happiness. Therefore, you and God are not working at cross purposes, but for the same goal.
The process of discernment, through often a struggle, in not complicated. It consists of four steps.