Syrah should be served at room temperature. The more structured styles will benefit from being poured into a decanter and allowed to breathe for up to one hour before serving.
Most Syrah from Australia and the Americas is meant to be consumed within one to four years of vintage date. French Syrah is almost always longer-lived; three to eight years from vintage for most, while sturdier examples can easily age a decade or more.
Buying (and drinking) an older bottle will typically get you a mellower softer wine with more dried fruit flavors and herbaceous notes. A younger wine will offer brighter, juicier fruit flavors and a firmer livelier texture.
Store bottles in a cool, dark place. While it is now common for wine makers to use plastic corks or screw-top closures which may be stored vertically or horizontally, those with the traditional corks should be laid on their sides to keep them moist.