Hardwoods make excellent material for turning. Apple, beech, cherry, maple, sycamore and walnut are examples of woods that turn well for face work (like bowls) and center work (like spindles). Growth rings on softwoods are spaced further apart, so those species are best suited only for centerwork. Some wood turners use green wood rather than seasoned because the former is easier to machine. Either way, seasoned or green, there are some characteristics to look for when choosing wood for turning.
Select air-dried rather than kiln-dried wood if using seasoned lumber. Air-dried woods tend to have fewer splits inside. Ask your wood supplier how long a particular piece was air-dried. One year per inch thickness of wood is a good rule of thumb.
Determine whether the length, width and thickness of the wood you are considering will accommodate the project you have in mind. While a tape measure can help, visually sizing the stock works well because rough dimensions are fine at the selection stage. Just make certain the stock is longer, wider and thicker than you envision your finished piece to be. If choosing to work with green wood, remember that it (and therefore your project) will shrink with time as water evaporates from the wood.
Examine the wood for splits at each end of the stock, and for cracks on each surface. Cracking and splits could indicate problems deeper in the wood.
Look at the grain pattern, color and any figuring in the wood. Determine whether you can incorporate any figuring, like burls or wavy edges, into your project or if they will interfere with the piece you will be turning. Each piece of wood is unique, and it is entirely up to you what will look best on the finished work.