Excellent book packed with info, tricks, highly illustrated--will save you time/money.
An ice tool evolved from the ice axe, however it is more specialized for use in ice climbing. It is sometimes referred to as a technical axe to distinguish it from a mountaineering ice axe. For ice climbing, The climber ascends an ice fall wearing crampons attached to ice climbing boots, with two ice tools, one in each hand. The ice climber keeps his weight balanced over the point where the crampons touch the ice. Each tool is then positioned, one over the other as he ascends the ice. The ice tool penetrates the ice and provides a grip for balance.The weight of an ice tool is important. The heavier tool will penetrate ice an packed snow easier. However, heavier is not necessarily better. The weight of an ice tool must be balanced by the ability of the climber to carry and swing it for hours at a time. Large climbers may choose a larger heavier tool, while a smaller climber may pick an ice tool that is somewhat smaller.
An ice axe is used during alpine and mountaineering, or while traveling across ice, glacier or snowfields. An ice axe is often referred to as a mountaineering axe to separate and distinguish it from an ice tool. An ice axe is used to assist with the assent, to grab rock edges, cracks, and ledges. It is an invaluable device for stopping a slide or fall.
The different types of ice climbing require a different tool design. For waterfall ice climbing the most popular length is 50 centimeters. Larger climbers may be able to use a slightly larger ice tool, around 55 centimeters. Smaller climbers may use a 45 centimeter tool. Waterfall and mixed ice climbing tool should have a modular design. The modular design allows you to change the pick, hammer, and adzes when they wear out. Some tools give you the option to use either a hammer or adze attachment. For alpine climbing, the tool has a straight shaft with a leash attached to the head. The purpose of a straight shaft is to allow the tool to be pounded down into snow as a secondary anchor. Never use an ice tool as the only anchor source.