I'm working on a jazz piece for my music major audition, and I'm seeing some stuff I've never seen before. I'm not particularly experienced with reading chords off of sheet music, so forgive me if these question seem idiotic.

First, what do triangles next to chords mean? Is that diminished? I know a circle means diminished, but is a triangle the same?

My second question, if I see something like "C-/F" does that mean either chord fits there? And what does the '-" after the C mean?

And third, if I see "F pedal-----------" under the staff, that means I let an F ring out under everything else for as long as that line goes, correct?
Triangle is indeed major 7 (for C: C E G B instead of C E G Bb)

C- I have no idea, but seems logical to be a min indeed, though I don't know what chord it is. The /F means indeed that it's the bass. Guitarplayer: don't mind the bass will play it in a band.

A pedal is often used for piano. So don't know if it's plausible for a guitar player. If it is it's as Jesse says.
Slash chords can be quite prominent in Jazz, so it's good that you asked here before going into your audition.

And indeed the minus symbol does mean "minor" as has been answered.

With the pedal, I wouldn't consider it a ringing note (and as previously said it could be something to do with a piano) but when I read your post I instantly thought it meant using an F as a pedal note, and as one of the chords has an F in the bass it seems to make a bit of sense.

(by pedal note I mean this: http://en.wikipedia.org/wiki/Pedal_point)
I wouldn't worry about the pedal or root notes really. If you're auditioning for a jazz major, the only notes you should really be worrying about are the 3rd and 7th - and obviously any extensions or alterations. If you're accompanied by a bass player or piano player, they really should be able to cover up all of those gaps.
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