I would suggest getting the Trevor Wye Practice book for the flute Book one (Tone). There are a lot of excercises in it to improve your tone and it really helped my a lot with my tone. As for music, there is a book called Twelve Fantasies for the flute by Telemann with 12 solos (with no piano part) that aren`t too difficult and are pretty impressive to play. Hope that helps! If you need to know about anything else, feel free to email me.
-Katie