Here is a list of the item slot numbers for your character:
Head = 1
Neck = 2
Shoulders = 3
Body = 4 (shirt)
Chest = 5
Waist = 6
Legs = 7
Feet = 8
Wrist = 9
Hand = 10
Finger1 = 11
Finger2 = 12
Trinket1 = 13
Trinket2 = 14
Back = 15
Mainhand = 16
Offhand = 17
Tabard = 19
Here is a graphical explaination of your character's item slot numbers:
