Mahogany is a common type of wood used for bookcases and , Walnut is also commonly used for making bookcases
cotton
Casters can be used on heavier bookcases that weigh up to about 200 lbs. Any more then that could become a little dangerous.
The most common element used in making filaments is Tungsten.
Wheat flour i guess
In most common cases red, black, and white.
Target's website displays a few cheap bookcases that could easily store fifty children's books and match a child's bedroom. If you are looking for used bookcases you can visit amazon where you will find many more choices of used bookcases with the same advantages.
The most common name for saccharomyces cervisiae is yeast. It is the most powerful species of yeast and is used when making wine, baking, and brewing.
sodium (Na)
Some wood types you could use include Mahogany, Oak, and Cherry wood. Each of these woods have certain qualities to them that makes them good for making bookcases. Oak is probably most frequently stained wood, but it has a nice look to it. Cherry will not easily stain or warp, it is similar to Walnut. Mahogany is the most commonly used wood for medium sized projects like this. It has a fine texture to it. Source: http://www.ehow.com/list_7283560_types-wood-bookcases_.html
For really cheap bookcases, the best place to look is probably Craigslist, but they will more than likely be used. If you want new bookcases, stores such as Target, Wal-Mart and Staples often have cheap ones.
Paying via credit card .
There are quite a few common alloys used by the car industry today. Some alloys include Iron, Copper, gold and aluminum. The most used in the making of vehicles would be Aluminum Alloy.