I highly recommend the Yamaha Flutes and Piccolos for the beginner and intermediate student.  The sound in all three octaves is fantastic and these instruments are sturdy, not needing constant repairs.  Especially if the student takes care of the instrument.   Here are a few suggestions and recommended models:

BEGINNER STUDENT MODEL
Yamaha YFL-221 Student model, all silver plated, plateau (closed hole), C footjoint.
INTERMEDIATE MODELS
Yamaha YFL-361H Sterling silver headjoint, silver plated body, footjoint and keys, french (open hole), offset G, B footjoint
Yamaha YFL-461H Sterling silver headjoint, body and footjoint, silver plated keys, french (open hole), offset G, B footjoint


FLUTE WORLD:

This is an amazing resource for flutists and students where one can find most published flute music, instruments and various flute and music accoutrements!

Flute World Co.
P.O. Box 250248
Franklin, MI, 48025
phone: (248) 855-0410
email: This email address is being protected from spambots. You need JavaScript enabled to view it.

NEMC: This company in New Jersey has given many of my students some good deals on Flutes.
phone: 1- 800- 526-4593