The most popular cams to use are:
Sony S600 6mp - very good quality pics. Amazing flash, it can be set up to 1000 ISO, so it is like having a slave flash. The downside is its speed. In the daytime it is around 2+ seconds and at night it can take around 4 seconds for it to take a pic. This hack is rather difficult, I wouldn't recommend it for a beginner unless they're really good at fine soldering.
Sony P41 4mp Very fast, 1 - 1.5 second trigger, flash is good, 2AA batteries take about 300 to 500 pictures, easy to modify - you don't have to solder to the actual camera.
Sony S40 4mp - flash and picture quality is better than p41 but it's zoom lens makes it a little slower - a little more than 2 seconds.
Sony P32 3mp - same flash as p41, little bit slower - about 1.5 to 2 seconds, modified just as easy as the p41.
Olympus d-380 2mp - This is can be modified for an instant trigger, or if you want longer battery life, trigger speed is about 3 seconds, easily modified by soldering. Makes a great IR cam
Olympus d-370 1.3mp - Same as d-380 except it's 1.3mp
Olympus d-360L 1.3mp - The main advantage to this one is you don't have to open up the camera to modify it, you just plug it in to the board. I've never used one of these so I don't know much else about them.
Samsung A402 4mp - A little on the slow side but still a good camera. Most people use these because they make great IR cams.
Here is a link on how to hack all of the above cams - http://pixcontroller.com/CameraMods.htm
The P41, P32, d-380, d-370, DC2.1 and A402 can all be modified to see IR. The d-380 and A402 take the best quality IR pictures. The p41 and p32 are nice because they don't need a slave flash(although it is recommended.) after converting them to IR. All the rest need a slave flash because the IR material put over the flash reduces the flash range.
Here are links to all the control board makers. Any board you choose is just as good as the next. Just pick one. If you don't like it, try a different one. Even if you do like it, try a different one for your next cam. It doesn't make a difference.http://www.pixcontroller.com/http://www.snapshotsniper.com/HomeBrewProducts.htmhttp://www.yeticam.com/http://www.whitetailsupply.com/WS-PIR-Board.htmlhttp://www.hagshouse.com/http://www.bfoutdoors.com/
Ok so you got your camera, your board, now you need:
-A case - once you choose your camera and board, you need to figure out (or ask) what size case you need and you can get those at lots of places - casesforless.com, ebay, trailsendcams.com, or any of the board suppliers. Most people use 1020, 1040 or 1060 pelican cases.
-Some kind of connector to hook the board to the camera- stereo plug, servo connector, phone plug, etc.
-Glass to cover hole over shutter
-Glass or lens to cover hole over flash - most people use a flash enhancer
-Fresnal lens - to cover hole over PIR sensor
-Stand offs and mounting screws - to mount the board to the case
Something to mount the case to the tree - most people used U bolts so they can use a python lock to lock the cam to the tree, I used a bungee mount from buyezweb.com or cinchy.com
I think that's a complete list of what you need, it'll get a lot easier and clearer once you decide on a camera and sensor board, until then you don't really know exactly what you need.
Let me know if you have any questions, or anyone else who builds can chime in.(let me know if I forgot anything)
You can also try these forums:http://www.jesseshunting.com/forums/http://hagshouse.ipbhost.com/forums/index.phphttp://realdealhuntingchat.invisionzone.com/index.php
Read the pinned topics and FAQs and search for newbie questions. If you can't find an answer, just ask, they'll answer any question no matter how hard, or how dumb it is.
Other good links you should check out:http://www.pixcontroller.com/Tutorials/ ... torial.htmhttp://www.iowawhitetail.com/ubbthreads ... o=&fpart=1http://www.easy3dcamo.com/building.html
<---LOTS OF GOOD INFO HEREhttp://www.shomeoutdoors.com/Trailcam.htmhttp://www.qdmaforums.com/showthread.php?t=9337http://www.gotchatrailcams.com/
<------ Complete trail cameras made by our very own Outdoorbob7.
Good Luck, you won't regret it.