For information on creating materials, see Apply color and shading to an object and Build and create materials using the Hypershade.
The following lists a few quick ways to assign (connect) a material to a surface.
In the viewport, you can be in either wireframe or shaded mode to make the connection. If you are in wireframe mode, make sure the cursor touches the surface when you release the mouse button, otherwise the connection may not be made.
To assign a material to a surface or surfaces via the viewport
Alternatively, you can select Assign New Material or Assign Favorite Material. The Assign New Material window appears that allows you to choose from the available materials, or materials saved in your Favorites list.
To assign an existing material to surface or surfaces via the Hypershade
Alternatively, you can also middle-drag and drop the material swatch from the Hypershade onto the surface in the viewport.
To assign an existing material to surface or surfaces via the Outliner
Shaders assigned to each object in the scene are now displayed.
In this example, the Killamari (squid) geometry is assigned the same material as that of the body of the Minion.