The electric field a distance r away from a point charge Q is given by:
E = kQ / r2
where points from the charge to the point where the field is being calculated.
The electric field from a positive charge points away from the charge; the electric field from a negative charge points toward the charge.
The field-line pattern reinforces the 1/r2 dependence of the field, as the lines get further apart as you get further away from the charge.