Acrylic Paint

White
Black
Yellow (lemon/primary)
Red (magenta/bright/primary)
Blue (phthalo, cobalt, or cyan, primary)

Check out this paint set on Amazon 
Add other colors/shades to have more options and versatility in color mixing.  I use medium body student grade acrylics. I DO NOT recommend craft paint. 

Brushes

Large Square 1"
Medium Square 1/2"
Small Round
 
Check out this brush set I recommend. 
Optional extra brushes, pallet knife, sponges, circle shaped objects for moons and suns. 

Canvas

Wrapped Canvas 
16 x 20
Panel Canvas
12 x 16

Other sizes or materials, be aware that other than canvas might not look the same, but anything goes! Read the full set up blog post here!