Picture of Selecting Timber for DIY Furniture Projects
Most home centers carry two species of construction lumber - some variant of a hybrid commonly called SPF (Spruce/Pine/Fir), and Douglas Fir or Southern Yellow Pine depending on your location.  The hybrid is lighter in color, less expensive and usually comes in fewer sizes.  Though the hybrids are cheaper, they are also softer.

Step 1: Grain Structure

Picture of Grain Structure
End grain orientation relative to the face of the board tells us the way it was cut from the tree and how it will behave.  Though construction lumber is not divided or sold by cut, it is easy to find the three common types of grain structure wherever construction lumber is sold.  Professional furniture makers pay particular attention to grain structure and quite often use all three types for different parts of each project.

*Flat Sawn - The most common and least dimensinoally stable cut.  Often used for floating panels and table tops.  Most likely to warp and cup, but generally considered the most visually striking.   If you know how to compensate for wood movement this is a suitable cut for any project.  A board is classified as flat sawn when the annual rings are parallel, or close to parallel to the face of the board. 

* Rift Sawn -  Commonly used for legs in furniture as all four faces show identical grain structure.   Also used for stiles and rails of doors.  A board is classified as rift sawn when the annual rings are around 45 degrees to the face of the board.

*Quarter Sawn - The most dimensionally stable cut.  Often used in stiles and rails of frame and panel doors and case sides.  Tends to look a bit boring.  Some people like boring.  Also used for drawer parts.  A board is classified as quarter sawn when the annual rings are perpendicular (or anything above 60 something degrees or something like that...google it) to the face of the board. 
vincent75202 years ago
Thank you for sharing … This is a very instructional Instructables !… ;)
pfred23 years ago
I have just walked out of some big box stores after looking at their wood. I'd start to go through one of their piles and get so frustrated I'd leave with nothing. Either that or I'd hold up a piece and think, this would be just the thing if I was making a propeller, or hold up another piece and lament perfect to make a bow with.

I swear the big box stores get reject lumber at reduced prices to increase their profits. There is something going on.
Jobar0073 years ago
Big box stores tend to have center boards because they are the cores left over from spiral cut plywood. You are better off getting a better quality board from a 2X10 or larger as a result. Nice instructions by the way.
rimar20003 years ago
Thanks for sharing!