Well, one piece of open source software I'll certainly be using is
Audacity, for editing audio files. It's as good as anything around for
simple podcast editing. GIMP is *not bad* for photo editing although I'm
much more familiar with Photoshop (and more qualified to use it).
I'd not consider GIMP "fit-for-purpose" for heavy/major image work. I use
it (because I work on Linux) and it is a pain in the... compared to
Photoshop.
When it comes to design for brochures and booklets
(for example) I'd use
Adobe Fireworks to create any graphics or images I'd need.
Have you tried Inkscape (FOSS vector image editor)? I used to use Fireworks
a lot and Inkscape turned out to be, surprisingly, a worthy upgrade on
that. But there can be a learning curve if you're only a casual Fireworks
user. Worth considering.
Hopefully the above answers Tom M's question too. Beyond those pieces of
software I can't imagine I'd use the rest of
Adobe CS at the moment -
although Dreamweaver may be useful for designing emails to members and
donors.
Oh noes! Please don't :P
Maybe try something like MailChimp's campaign editor (literally the best
mail design tool ever!). Dreamweaver sucks bad enough for creating
websites, let alone email ;) In fact - it might be worth looking at
MailChimp for the Chapters mail campaigns/correspondence.
On the main topic: I have a few CS Licenses kicking around which may
include some of the software you need (no promises, I just know they exist
somewhere, not the state of them :P). Let me have a look.
Tom