Right Hand Rule

The right-hand-rule gives you the correct direction when figuring out a cross-product. If you have a formula like $\vec{A} \times \vec{B} = \vec{C}$, then pointing your first two fingers the in the directions of the first two vectors, your third finger will point in the direction of the third vector (answer). But you must do it in order! So $\vec{A} \to$ thumb, $\vec{B} \to$ index finger, so the result $\vec{C} \to$ middle finger. Just make sure you use your right hand!