I was going to leave this bit till the end, but i thought it should go up top, its quick tips, and might save you from reading my long and possibly geeky and self absorbed little piece.
1: Stabilize, Stabilize, Stabilize.
For the love of all that is holy, keep that camera still. Stuff in the frame can move, the camera really shouldn't, it leads to nasty blurry photos that even a dog would pronounce dodgy. Do it by any means, wedge you iPhone up with random objects, use a tripod, use tape, anything, just don't let it move.
Light is everything, you could get freaky like me and start using flashlights to augment you lego shots, or just use a set of flashes to get a nice clean shot. Experiment with it, and make sure you have enough, otherwise blurry or noisy photos will result.
3: Its ALIVE!
Your lego is alive, you've created a fire department that goes to fires and races down the wrong side of the road, don't be afraid to get down on the carpet with your lego and take pictures of your fire trucks like the local fire buffs would.
Firstly before we jump headlong into pressing shutter buttons, a little bit about how photos work, please skip ahead if you know what i'm about to say. And remember that i'm only any good at taking them, i'm no photoshop expert, on all things graphic design and photoshop i'd say Dakota would be your man.
A photograph is an exposure of light onto an imaging area, IE Film, or a digital sensor. If we just assume that no one is shooting lego on film (if you are brave soul, i commend thee) we assume that that imaging area is a sensor. I doubt you want to read the geekyness associated with imaging sensors on a lego page so i will skip all but the bare necessities.
So we have a sensor and we have a lens to project your image onto it. from this point onwards 3 main things control the exposure that hits that sensor.
Shutter Speed: How long the photo took to make
Aperture: How wide the opening that allowed light into the camera was.
ISO / ASA / Film speed: How sensitive the camera was.
These things explain why your pictures may be blurry, dark, too bright, noisy, and how much is in focus.
So Shutter speed, shutter speed affects both brightness, and motion. A fast shutter speed in a well lit space will freeze motion, catch that baseball tack sharp as it leaves the bat. Show shutter speeds will allow anything bright enough that moves to create a blur, the classic shots of the head and tail lights turning into trails on the freeway.
Fast, freezes the plant.
Slow, everything that moves turns to blur.
How does this effect lego then? Lego doesn't move right... Hmm, we'll talk about that one later.
Aperture, Aperture is the size the iris on your lens, or the hole is that lets light to the sensor. it is measured in a F stop. if your experiencing lenses with a T stop, your looking at movie lenses, and should't be having to read my explanations. The smaller that number, the bigger the hole and more light gets in, backwards I know... It affects again overall brightness, and it affects how much of the image is in focus, IE depth of field.
This one is really important to lego, i notice it time and time again with people that shoot their lego on DSLRs. Because lego is so tiny what would be a large depth of field when taking a picture of your cat, now becomes tiny again, this is why only the front bumper of your truck is in proper focus.
An example, of how just changing the aperture put the whole truck in focus.
ISO / ASA / Film speed.
This is that overlooked little setting on pretty much anything that takes a picture, my crappy nokia has it, my 35mm film camera has it...
This controls how sensitive the camera or film is, and therefore controls how bright the exposure is, and has the side effect of controlling, grain, noise and dynamic range.
A low ISO will give the cleanest shot, it will also effect how much difference in light levels your camera can see, google dymanic range to get geeky here.
http://www.flickr.com/photos/38285596@N02/8543721454/ A shot with a high iso, showing how the image has become grainer, just as it would with film, it also has a little bit more digital noise.
How does this one affect lego photos.... Its what lets you stop them being so horribly noisy!
These three things all affect how bright the image is and must be successfully blended to create the shot. A slower shutter speed would allow a brighter frame so that you could use a smaller iso to get a more finely detailed shot, or so you could use a smaller F stop to get more of the photo in focus. In reverse, you might decide to use a really high iso and have noisier and grainer shots so you could freeze the action at a basketball game, or in my case freeze the dog before she ran off.
And before we finish the geeky section another setting that all cameras have, White balance. This is why sometimes your photos look a bit blue or maybe look like the burning pits of a very orange hell. This tells your camera what white is supposed to be when being lit by whatever is lighting your shot, IE a lightbulb or the sun, we can sometimes see this color difference but most of the time our brain is set on very good automatic.
For example normal tungsten lightbulbs are very orangey, so the camera sets its self a bit blue to compensate, when set incorrectly the camera gets things a little muddled, simple rule of thumb, set it to Auto, unless shooting videos or until something looks weird, at this point set the camera to the most appropriate setting. the reason for video being that the camera might decide to change halfway through your shot and all your colors go a bit weird.
Now thats the geeky bit over with phew...
So taking pictures of your creation first of all, Tom i'm sure has said much of this before, his shots are always perfectly lit and you know what your looking at, go look at his gallery and see how nicely its all lit.
This sort of setup of camera on tripod and being well lit is perfect for showing the world what you built. My only tip here ontop of looking at Toms shots is to try to use a longer shutter speed as nothing is planning to move allowing you too use a deeper aperture, bigger F stop to get the whole thing in tack sharp focus.
Where you position everything is really up to you, just try to not make it distracting, if backgrounds are distracting, just open up the aperture to blur it all out if you can. And be aware of shadows if using single light sources.
But where i'm really interested is creative photos of lego, and of lego scenes.
here all the rules for taking creative photos apply, but with a special twist of your protagonists being about an inch tall
So... some examples of cool things to try, i use the examples to demonstrate my ideas, i'm not saying i actually took good shots here at all, its the idea that counts.
Taking these sort of shots really helps give a human quality to your lego world. try zooming in a long way to get a nice shallow look and creatively light the figure, be careful of glare of the plastic though, i often have trouble with this. Take note from seriously cool portraits on proper photography sites and try and get the same thing across, remember composition ideas here too, try to avoid dead centre shots unless its a specific look your going for. example (Up in the face with a fisheye).
Slow Shutter Speeds.
Slow shutters help you to add motion to your work, here i've got a police car that I shot in focus and then moved under the lights to give the idea of speeding to a call. The other is the spinning chopper blades, spin the blades and set of the shutter, job done.
When you use wide lenses, or zoom out a long way most lenses suffer from whats called barrel distortion, where everything looks a bit bendy, it also exaggerates the spacial difference between items, this can lead to some very dramatic shots.
Just remember to really get the effect you need really wide lenses, in the case of the quantum the shot was just way too big, so i cropped the truck out of the centre.
At the extreme end fisheyes or a fisheye effect, either screwed onto your camera, or done in post in some very scary photo editing software.
All about showing the department is alive.
Just try to imagine being a journalist or fire buff on your scene and try to get the camera low and into the action, i often can't get as close or as low as I want, this is something i'm really working on.
Shallow Depth of field.
Using a bigger aperture, small f stop lets you make things shallower, if you on a dslr or decent compact this allows to isolate the thing your showing to the viewer, here in a crowded trauma room Bruce is introduced to someone, i only really want you to look at the things in focus, but i still want you to feel like your in the room, so i blurred it all out.
Cool action shot lighting.
I have no idea where the ideas for these sort of thing come from, just start messing around with a flashlight I Hope thats given you some ideas, I really love taking pictures of lego Don't be scared to take the camera out of auto and have some fun.