Before undertaking any major concrete work, it's nice to go into the project with an idea of how much it's going to cost you. First of all, concrete prices are not set across the board. They will vary from locale to locale depending on going rates for materials and labor. Also, as with any major home improvement project, it's a good idea to contact several contractors in your area to compare rates. All that being said, however, here is a baseline for what you can expect when you start researching what your concrete prices are going to run.
Grading: Before any work begins, you'll need to make sure the area where you plan to pour your concrete is level and ready for work. That means grading the area. The necessity of this step varies depending on your worksite and the size of your project, but if it is necessary to level things out you can expect to be charged about $45/hour to get it done.
Laying A Foundation: Any large concrete project is going to require you to put down a base to pour the concrete onto. Usually this means laying a gravel base before the pour. Expect gravel to run about $12 per cubic foot delivered to the work site.
Labor: Unless you're a sucker for back pain and sore muscles, and have a handful of very dedicated friends, you're going to have to pay someone to build the forms, work the pour, and perform the finishing work. Typical labor costs will run in the neighborhood of $1 per square foot.
Reinforcement: In order to ensure the longevity of your new concrete project, you'll need to install some reinforcement after the forms are built to prevent cracking and other damage later on when your concrete expands and contracts with the weather. Wire mesh, plastic mesh, and steel re-bar are all commonly used materials that cost about 10 cents per square foot. Your contractor will be able to advise you as to what is the best material for your particular project.
Concrete: Concrete prices will make up the bulk of your cost for any large concrete project. A good ballpark figure is $70 per cubic yard of concrete.
Figuring the Final Concrete Cost
These numbers should give you a good idea as to what each aspect of your concrete cost is going to end up being. If you're unsure about how much of each material you're going to need, measure out the square footage of the area you're planning to work with, and then call a concrete contractor in your area. They will be able to tell you about how much of each material will be required. After that, it's just a matter of doing the math to figure out total concrete prices. Also, keep in mind that these rates are for a basic, no frills job. If you're thinking about more decorative concrete work, including stamping, coloring, or other more detailed finishing projects, expect to pay extra for those services. 
Matt Goering, formerly a carpenter and house painter, is a freelance writer for the home improvement industry who has published over 600 articles.