A good jazz song for a thing at my highschool! ~?

Canteloupe Island - Herbie Hancock good lilting tune.....

Blue Monk - Thelonius Monk (although it probably can be slotted into the 'blues' bracket better)

If you're a singer.... God bless the Child - Billie Holiday

Or a great song by Nina Simone - Sinnerman

Take 5 - Dave Brubeck

*"This Business of Love" - DoM.I.No (Male Singer)
*"Gee Baby, Ain't I Good To You" - Susan Boyd (Female Singer)

Cameleon by Herbie Hancock
Blue train by John Coltrane

really depends on the caliber of the band.
If you have a tight sax section try Time Check - buddy rich
conspiracy theory - mike tomaro is an awesome funk that's pretty easy except for syncopation except for a crazy trombone soli. that song is a party though.
For higher level band where you have all good section try alot of the Gordon Goodwin Phat Band charts are nice.
For a lower playing level try Straight No Chaser - Buddy Rich
Or limehouse blues - although i don't know the composer

flaming sword- duke ellington

''Running Away'' by Roy Ayers.
''Fallin Like Dominoes'' by Donald Byrd.

Song for my Father by Horace Silver

definitely do a GORDON GOODWIN song =)

here:

High Maintenance-Gordon Goodwin's Big Phat Band
Hunting Wabbits-Gordon Goodwin's Big Phat Band
Horn of Puente-Gordon Goodwin's Big Phat Band
The Jazz Police-Gordon Goodwin's Big Phat Band

HAVE FUN!!! xD