So you want to get into the photography game huh? Before you run out to the best buy with a fist full of cash you need to edumacate yourself son! The first think that you need to decide is what kind photography you spend most of your time with. A person who wants to document that "totally awesome" frat party for their facebook page is going to want a different sort of camera than a working pro who is burning off several thousand frames a day. The best way to pick out a camera is to break down the various features and then find the model that has the features that you want.
Point and Shoot Vs. dSLR
The first decision is Compact vs. dSLR. chances are that you have owned or at least fooled around with a compact digital camera before. They are easy to use and relatively cheap so when you drop it in your drink at the bar less tears will be shed. Some of them allow for manual control of the settings but they lack the creative control of a dSLR. If you think this type of camera might be for you then stop reading now, this will be the last mention of this camera type.
dSLR or digital Single Lens Reflex describes a camera that allows you to look at what you are shooting though the lens via a mirror and viewfinder (reflex). The camera consists of two main parts the body, which houses the electronics and light sensitive chip; and one of a range of interchangeable lenses allowing the cameras versatility to grow with your budget.
Too often megapixals are seen as the sole factor on the quality of image a camera is capable of producing, this is not true. In the past megapixals were a big deal but the truth is that almost modern cameras are capable of producing poster sized prints in film quality. Infact, for reasons I will not get into here, a 6 mp camera will product a better 8X10 print then a 10 mp camera in some conditions. The true limiting factor in image resolution will have more to do with lens quality and post production. The current standard for resolution is around 10mp, for most situations you can be fine with 6 and both Canon and Nikon make 20+mp Super Cameras. If you are considering something in that range then you already know your stuff.
The bad news here is that once you pick a system, it gets harder and harder to switch with every piece of gear you buy. The good news is that all of the choices here are so close that you can't pick a loser. The important thing to note is not to pick a system based on who makes the "best" camera right now as this tends to change from month to month, no joke. You should instead pick a brnad based on how the entire line offered by that company will fit your needs. For instance, Canon makes a number of cameras with huge sensors perfect for high res posters but their lenses cost about 2-3 times what the equivilent Nikon lens costs. Sony makes a series of excellent cameras that can use older Minolta lenses, of which there are a ton used online. The downside of this is that Sonys own lenses are not nearly as good as Nikon's or Canon's. Sony and Olympus also have Image Stabilization build in to the camera body, where as Nikon and Canon have it build in to the lens. This means that any lens on a Sony or Olympus with be IS where as this feature is only available on Nikon and Canon's very expensive pro glass. The down side of course, is that you can walk into any shop down the road and find Nikon or Canon vs most likely having to hunt on the internet for some of the lesser known brands.
There are a million more factors to making an informed purchase. I will leave the rest of the research to you but this is enough to get you started. Below are a few things to further consider before buying.
1 Consider the whole package.
Most often not everything that you need comes in the box. At the very least check into the price of a spare memory card or two. Other things that you SHOULD purchase with your camera system: A cleaning kit, camera bag, spare battery, flash, editing software such as Photoshop or Lightroom. I know that it is tempting to spring for the camera and leave the rest at the store but these are really the minimal pieces of gear to fill out your bag ESPECIALLY the editing software. Remember, clicking the shutter is only the first step to making a great image.
2 Buy good glass.
Often retail store will package and expensive camera with a so so lens and add $200 to the price tag. if you are a true beginner this will be ok but if you know your way around an f stop then it may be best to purchase the lens and body seperate. (see #3) My advice is to start with the best all around lens you can afford. The lens may equal half of you camera budget. For instance if you want to spend $1200 on a camera drop $500 of that in a nice 18-135 F:2.8 . Buy it new and get a warrenty. This lens should last at least 10 years if you take care of it.
3 Buy a used body.
Here is where you can save some money. Unless you are a Pro, your camera will be far outdated by the time you wear it out. Most cameras will last 100,000+ actuations with some pro cameras going for 250,000+. There really is no sense in buyin that cutting edge camera right now especially when you can buy a camera that came out a year ago used with 20,000 actuations for 1/3 the price. You'll get a nice camera at a great price and won't be stuck still making payments on that brand new one for years to come, and you will be more then ready to upgrade by the time it wears out. A good example: The Nikon D300 cost cost about $2600 when it came out in 08 now a new one costs $1200 and a used one can be had online for $900.
4 Buy good stuff.
I know I just told you to buy a complete kit right away, but that is only partially true. I know money doesn't grow on trees (especially right now) but don't worry if you can't fill up that bag on day one. A camera and a lens is all you really need. What I mean is that yes, the bag and the cleaning kit are important, even vital tools tools for a photographer, but don't miss out on the experience that having that camera in your hand will give you. You won't learn anything from that wad of cash just setting in the bank for you save an extra fiver for a lens cloth. Buy the best camera you can afford now. Then save up for a decent camera bag. Then some software. etc, etc. Don't buy a so so camera so you can also afford a so so flash. Got it?
5 Use your gear.
The great thing about digital is that once you have a camera in hand, the picture are basically free! In the old days (when I learned) film cost $4 for 24 exposures and another 4 to get prints. now you have instant feedback on what you are doing. You can fill up a card with a couple hundred pics and only print the few ones that you really like. You can read all you want (I do) but the best way to get good is to shoot tons and tons.
I know that I probably missed a ton of stuff but I get awful lazy at night. You could right a rather large book on this one and it would be outdated before it hit the shelf. Shoot me an email (firstname.lastname@example.org) if you have unanswered questions and I may make a second post about it. P.S. I shoot Nikon