The finish will help define the type of wood to be used.
You would not want to use an exotic hardwood with a beautiful grain pattern, and then cover it with paint.
In my mind that would down right criminal.
You also would not want to use a common pine for a project that you intend to stain.
There are several options available to you when you paint your project, oil based paints, Latex paints and Milk paints.
There have been a recent addition to these choices, Low or No VOC paints.
For years oil based paint was the choice of most professional painters however, Latex seems now to be the more popular choice.
Milk paints are a throw back to earlier times.
The authentic colors are often seen on many antiques.
Unlike oil or latex paints that come premixed, Milk paint is sold only in a powdered format.
Using Milk paint is easy; simply mix the powder with water.
Mix only the amount you need as powdered Milk Paint will not keep.
A new option for Milk paint is the Pre Mixed Milk paint from General Finishes.
There is a top coat available for both options that protects and deepens the finish.
Low or No VOC paints, are the newest entry to the paint options, as an answer to the desires for a greener planet.
VOC or Volatile Organic Compounds are part of the air pollution problem.
Adding colors to some of the No VOC paints, adds VOC back into the paints, so be sure to check with the manufacturer of the paint you choose.
The Low/No VOC paints and the Milk Paints are safe for use around children, and those allergic to the latex or oil paints.
Ask any professional painter, what is the most important thing about any painting project, and the answer will be preparation.
To get a good finish on your project, be sure that you completely sand and clean the project.
I sand a painted project to 200 Grit, unlike a stained project, which I only sand to 180 grit; too much sanding for a stain finish will cause the stain to set on top of surface instead of penetrating into the wood.
The other thing the pro's will tell you, use quality primer paint.
The old school of thought was the primer must match the final coat, oil primer for oil paint.
The current thoughts are to use a good latex primer for all interior projects, and reserve the oil primer for exterior projects.
The oil primer will seal the wood better then the latex primer.
Latex is the preferred topcoat paint for both interior and exterior.
Let the primer dry completely and then sand it again.
The residue will be chalky, so it is recommended that you use a good vacuum to clean the surface before applying a topcoat.
One more thing, use a good quality brush.
Save the cheap throw away brushes for applying stain.
There is no reason to ruin a project with a brush that comes apart while you are painting.