Painting in Acrylic is a different experience to Watercolour and it is an ideal medium for beginners, because mistakes can literally be painted over, taking advantace of the opaque nature of the paint. Watercolour is not so forgiving!
Acrylic paint can be used like watercolour in thin washes using water or glazing medium, but has the advantage that the tone of the paint does not change during the drying process like watercolour does.
There are many brands and types of acrylic paints and inks and crayons availablle along with a wide range of additives. For instance the medium can used in different thicknesses and opacities, to behave like oil or watercolour paints. Brushes, palette knives and other application methods can be used in acrylic painting.