As I was preparing for 1 Samuel 16, I was comforted by the fact that God didn't give Samuel all the details about what was going to take place when he got to Bethlehem.  I like to know all the details before I do anything.  That is mans way.  See God isn't going to give us the play by play before we go and He has been growing me in this area.  If God was going to show us everything that was gonna take place, maybe we wouldn't go.  The Lord wants us to be relying on Him and if we knew the out come, if we had already seen the big picture we probably wouldn't really be dependent upon Him.  When Samuel got to Jesse's house the Lord instructed Samuel what to do.  Each step of the way the Lord revealed more to Samuel, all the way up to the point when he anointed David.  Samuel really didn't know what was going to take place, not all the details, but he went any ways.  It was very encouraging for me, a very detail oriented person to see Samuel's faith and the Lord leading.  Hope it encourages you as well.