I've spent quite a bit of time in the jungles of Central and South America (but never the Amazon), the Congo River Basin, SE Asia, The Philippines and a few other places. Hopefully, Pict will chime in, as I consider him our resident jungle expert and he teaches survival down in Brazil.
How long will you be gone? What will you have available to you locally? Is there chance for resupply or are there stores not too far away? You need to give details to get more specific advice.
You've gotten good advice so far. If your a medical doctor you'll be sorted on the FAK and meds, so I won't go into those (but do take the malaria pills, if it's a danger in your area).
A hammock is an absolute must in the jungle, and you never sleep on the ground unless you don't have any other alternatives. You will get eaten alive on the ground. Check out something like the Hennessey Hammocks (civilian and much improved versions of the Army's jungle hammock) as they provide bug protection too and are very comfortable. If you're sleeping in the village then this may not be necessary, but it's nice.
Bring some good sandals, like Chacos, Tevas, etc. You'll probably have a lot of down time and sandals let your feet breathe and help to prevent jungle rot and are nice for river crossings.
Bring DEET and a lot of it. I detest the stuff, but it's the only thing that works in the jungle and the jungle is the only place I'll use it. Keep it away from synthetics because it'll eat through it. Dusk and dawn is when you'll need the most protection. You might consider getting some permethrine. You spray it on clothes, hammock, head net, etc. and it kills the bugs for up to 2 weeks.
Don't wear shorts and short sleeves (unless swimming). This is counter-intuitive because it's hot during the day, but you want insect and cut protection. In the jungle small cuts become infected rapidly due to the humidity. I also wear gloves when travelling through the jungle, to protect my hands from cuts, as your hands will take the most beating when clearing vegetation. Find a leather pair that don't dry hard (I think that would include pig, deer and elk, but you'll have to research that on your own).
A machete is a must have item and typically in the jungle longer is better. I would look at something in the 22 or 24" range. They'll be locally available but quality may be questionable, so consider bring one of your own. Also ditch the leather sheath if it has one, as this will rust your machete like crazy. The crappy US Army plastic sheaths are good for the jungle as are custom kydex ones. Also bring some sort of file to sharpen with and something to protect from rust (Condor makes stainless machetes, which negates the worry about rust, but I've never used them). In the Army we used vaseline, but you can use mineral oil or something else that is edible so you can use the machete for food prep too. Watch the natives use their machetes and learn from them. They can do everything with just a machete and makes me a little embarrassed about my knife collection and all of my highly specialized blades. Condor, Ontario and Tramontina all make good machetes that are cheap and I'm sure there will be other suggestions from the guys here. If you're not used to machetes then keep a bleed kit close at hand just in case (better safe than sorry). Roller gauze and a compression bandage ought to do it, although a SWAT-T would be better so that it can also be used as a very effective tourniquet.
Head nets can be sanity savers due to the buzzing insects that like your nostrils, eyes and ears. Wear it with a military style jungle hat or get the Outdoor Research version which has a spring ring around it to keep the net off of your face so the bugs don't bite you through it.
If batteries will be readily available then disregard the following advice: make sure all of your electronics use the same battery then get lots of lithium batteries which are much lighter and last much longer. Alternatively you can get nickel metal hydride rechargeable batteries and a solar charger from Brunton or Solio. You may want to bring a crank flashlight as a back up, but all the ones I've seen so far have been kinda dubious for quality.
Headlamps beat flashlights for just about every application and can be a life saver if travelling through triple canopy or at night so that your hands are free to swing a machete or protect your face.
How will you treat water? Pumps are most convenient (put water in a bucket and let the dirt settle and also use a doubled over bandanna to further pre-filter. The dirty water there will eat up your filters). The water may be too dirty for UV purifiers. Chemicals are expensive for long term use, but if you do go that route (and you should carry some with you for emergencies), go with chlorine dioxide, like the Katadyn MP-1 tabs.
If you'll be taking any excursions into the jungle then always have a survival kit and a machete with you. Tourists get lost in the jungle all the time when just going for a stroll away from their resort.
Have a good map (if you can find one) and a good compass with you, although the jungle's density can make land nav a challenge, to put it mildly. I also like a pin on compass on my packs shoulder strap for general direction finding and I tend to use this more in the jungle as terrain will often dictate where you go.
Be nice to police and military as they are often the only law around there and they tend to abuse it in rural areas, where their power is absolute.
I'll think of some more advice. Send me an email through my name and I'll send you an adventure travel guide that I've started writing (it's very short so far). A lot of the advice in there is good for what you're doing.
Good luck! I envy you!
