Find the resultant force

We have two forces: $F_1 = 8$ units (acting horizontally) and $F_2 = 5$ units.
The force $F_2$ is at an angle of $30^\circ$ from the North axis. Since the North axis is perpendicular to the horizontal force $F_1$, the angle between $F_1$ and $F_2$ is $90^\circ - 30^\circ = 60^\circ$.
Let $\alpha$ be the angle between the two forces, so $\alpha = 60^\circ$.

The formula for the magnitude of the resultant of two vectors $F_1$ and $F_2$ with an angle $\alpha$ between them is:

The magnitude of the resultant force is $\boxed{\sqrt{129} \text{ units}}$.

The angle $\theta$ is the angle between the resultant force $R$ and the horizontal force $F_1 = 8$ units. Consider the triangle formed by $F_1$, $F_2$ (shifted), and $R$. The angle opposite $R$ in this triangle is $180^\circ - \alpha = 180^\circ - 60^\circ = 120^\circ$. The angle $\theta$ is opposite the force $F_2 = 5$ units.
Using the Law of Sines:

The direction of the resultant force is $\boxed{22.41^\circ \text{ relative to the 8-unit force}}$.