Recorder is probably the easiest of all wind instruments to learn. It requires very little in the way of breath to play and is not difficult to get sounds.
Many schools use the recorder as the instrument of choice to begin lessons in general music classes because children will learn basic music reading while learning. It is also probably the cheapest instrument you can possibly buy with even good plastic ones being less than $5.00.
Fingering patterns on recorders are very similar to fingerings on modern wind instruments such as flute, clarient, saxophone, and oboe and so the basics will stand a student in good stead for more advanced instruments.