Composites! My recommended source for resins, glasses etc.
http://www.uscomposites.com/epoxy.html <-- the resin (their brand - west systems is great, just expensive)
We used the medium hardener/epoxy which gave us a pot life around 20+ minutes at 75ish degrees F and cured overnight or so. I highly recommend the pump attachments to make measuring an exact science.
With one exception, every batch we made came out perfect. That exception was a set of test samples that took four days under heat lamps to cure. We think that there wasn't enough hardener to kick properly. The stuff was used to make HPV fairings for the past two years with a K-mat core. The picture here is last year's fairing that got vacuum bagged.
Funny story, the gentleman that assisted us (with his experience) apparently knows Burt Rattan - you know, the man that built SpaceShipOne. The window idea was just an off the cuff joke we had that eventually made its way into solid works and ProE -- and then when no other window design was thought up it was cut out :P
When I remember where we got it, I'll post our source for Micro Balloons (air encapsulated in glass) and K-mat (square scored foam core backed with a very thin layer of glass weave).
Going from memory - the fairing below used 3mm Kmat core with S-class woven glass (can't remember weight). We might have used E-class glass too (not sure) because we have a roll of it from last year. Flanges (not shown) are used to support the upper canopy in place. They are made from glass with a "coremat" core. The lower removable section also has a flange to hold screw bosses - this was made from the same "coremat" setup.
The whole thing was layed up on a male plug that was made from Styrofoam that was cut on a waterjet in 1 inch thicknesses - glued together - sanded - filled - glassed (to get it nice and smooth) and then covered with a wax mold release. When everything was layed up, a vacuum bag was cut for it and I believed they pulled 10psi (they went higher and the foam started collapsing).
Now you may think I'm sharing trade secrets or something. Maybe so - but the experience we had access to was so helpful (this stuff looks a lot easier than it really is). I'm told that enclosed rear wheel was pretty difficult -- and it got quite a bit of attention at the competition :P
As I find more pictures and videos from past projects -- I'll post what I've learned. If you have any questions, I'll try to answer. Just keep in mind I'm not an expert :P
PS: Next time you ride Dr. Doom at Universal Studios, Orlando -- look up at the decorations and such on the ride. Our experienced friend did all of those - yes, those pyramid/circular thingamabobs are fiberglass (he still has the molds :P). He came in 100lbs underweight ;)