Remember, a wrist wrest is to support your wrists while "resting" not while typing. Your wrist should not be positioned on the rest while typing as this leads to bending of the wrists and awkward postures.
Most new computers come with a standard keyboard and mouse. For many people, these may work fine for a while. But remember - the selection of a good ergonomic mouse can make a significant difference in mousing comfort during everyday computing.
Many ergonomic triggers leading to musculoskeletal disorders are present while mousing: excessive force from hitting the mouse buttons, repetition with long...
A mouse should be positioned as close as possible to the keyboard to avoid reaching or sitting with an outstretched arm, and at the same height to avoide awkward arm positions.