You can have all the woodworking plans in the world but if you don't know how to pick out wood then your projects will not turn out good. We have broken this down into two parts the next one you'll get tomorrow - but this very important don't side step this process. Here is a basic guide for wood picking.

The two basic categories of wood are hardwood and softwood. There is also manufactured wood like plywood.

What you use for any given project depends on various factors: strength, hardness, grain characteristics, cost, stability, weight, color, durability and availability. Usually beginning woodworkers start out with softwood such as pine. It's soft and easy to work, and you don't need expensive tools to get good results. It is readily available at local lumberyards and home centers. It has it's limitations in furniture making; it is a soft wood and will damage easily.

Softwood is from an evergreen or coniferous (cone-bearing) tree. Common varieties are pine, fir, spruce, hemlock, cedar and redwood. These woods are mostly used in the home construction industry. Cedar and redwood are excellent choices for outdoor projects, while pine is often used for "Early American Country Style" furniture.
Pine and most other softwoods will absorb and lose moisture more than hardwoods so are not as stable. Purchase the lumber at least two weeks before starting your project and keep it indoors.

You will find that softwoods are sold in standard thickness and widths, for example a 1 X 4 will be 3/4" thick and 3 1/2" wide similar to construction materials. The material will usually be priced per lineal foot and the price will increase accordingly for the wider boards.

Hardwood lumber comes from deciduous trees, the ones that shed their leaves annually. Popular domestic species are oak, maple, cherry, birch, walnut, ash and poplar. Of these common native hardwoods, only red oak and poplar are usually stocked in home centers and lumberyards, the others have to be obtained from specialty stores. The material stocked at home centers and lumberyards is usually sold in similar dimensions to softwood and by the lineal foot as well.

At specialty stores the thickness of hardwood lumber is specified in quarters of an inch, measured when the wood is in a rough state. The thinnest stock is 4/4, representing 1 in., and the thickest usually available is 16/4, representing 4 in. Rather than being milled to specified dimensions, like pine, hardwoods are sold in random widths and lengths.
Working with hardwoods is quite different from working with pine; you cannot drive a screw through hardwood lumber without first boring a pilot hole. Cutting and planing hardwoods requires extremely sharp tools.

Hardwoods are good to use when building furniture. Oak and ash are known as open-grain woods. These species have alternating areas of relatively porous and dense wood, when stained the open-grain areas absorb the color readily while the harder areas are more resistant. This accentuates the grain patterns, creating a dramatic effect.