In this day and age there are so many different paints to choose from that anybody that only slightly know what to choose can walk away with a headache. Paint falls into two main categories, oil based and water based. Stains and also varnishes also fall in these same categories.
Paints that are oild based come in gloss, semi gloss, or matte. Oil based paint happens to wear well and makes for a good cleaning surface. It is good to use oil based paint on doors, windows, or jsut about anywhere that needs to have a finish that provides a protection. You can use oil based paint on wall and ceiling if you require a tough washable surface, like paint cans usually. It is never a good idea to paint over top of wallpaper because it makes it harder to remove from the wall.
Water based paint is much easier to work with this is because the brushes and all painting tools can be cleaned using only water, which is similar to paint cans to most people. It is the choice paint for walls and also for ceilings and for textured surfaces outside.
When painting any new surface it is best to use a primer. By doing this you will prevent any paint from being absorbed. Also by doing this it gives the paint something to stick to. The primer the you choose should be manufactured by the same company. For a hint you can use water based primer for oil paint but you can’t use an oil based primer for water based paint. The number of coats the you will need depends on how porous the surface is, and the thickness of the paint you are applying, like paint cans usually. The quality of paint also has a factor to the amount of paint you will need also.