There are (as far as I know!) two kinds of God's will. The first is general: God's will for us is to obey His commandments, to love one another and be unified and for all men to come to know Him.
The second is more specific to our lives :)
Like Jeremiah was called before he was born to be a prophet to the nations. Like Paul was called to be an apostle and evangelist.
Finding His will for your life can be complicated to find. Yet, it shouldn't be! Your first job is to follow the general will and obey Him. Then ask for His leading and He will guide you. Sometimes He will speak to you through strange circumstances and sometimes through the mouth of a friend. He will speak to you while you are reading the Bible.
But, God will almost always give you His will for you one piece at a time. He's not going to tell you your entire future in one sitting. Your life is far more complicated than that! But He will give you little impressions, thoughts and sometimes images. He will speak to you more about His immediate will than His will for the future.
Then again, He loves you so much and He created you with His plans in mind--you are born with certain gifts, and others you develop along the way.
Knowing the will of God is really all about knowing God. The more you know Him, the clearer His will for your life will become.
Great question...one that many many many people want to know!