Hi Carole and welcome to the initial problem, and that is into which brand to invest. I say invest, because it is (or soon will be) an investment of truck-loads of cash to get the best available. As far as technology in the DSLR market goes, you really only have two serious choices, Canon or Nikon. These two tend to leap-frog each other in DSLR technology, and there is not much to choose between them.
Find the one that suits you best, considering size and weight of actual camera, pixels required, price, features needed and all the rest of the stuff to consider when making such a decision, and then put your decision on hold for a few minutes. Take a look at the lenses you require (and may require in the future), and again put the decision on hold for another few minutes. Then ask someone knowledgable on both brands, and especially on the different methods of construction of the most important part of any camera system, namely the lens. And the penny (or pound) will eventually drop. The reason that Nikon lenses, especially the longer ones, are more expensive is because Nikon uses a method that creates a better quality of optics. Now there are better quality optics available from other companies - just find out who built the Hubble telescope - but no company produces both the range and quality that Nikon produces, that attaches to a high-quality DSLR camera.
So you can make the popular decision, join the other lemmings of the world, and go with one brand, or you can stand out from the crowd and have your pictures stand out from the rest if you so choose, but only if you go for the other brand.
One day, DuQues will see the light and change brands to what he should have chosen in the very beginning
(Nikon, of course)
On a more serious note, you cannot go wrong with either the Canon or Nikon brands. DuQues is correct when he says that the long Nikon lenses are slightly more expensive, but there is a school of thought that believes that the Nikon lense optics are superior. Do not be led down a path that may not be the best for you...... Choose the lenses that best suit your primary applictions, and only then decide on the camera body to buy......and do not be swayed by others too far from what you want, need, and can afford....
Damn, there goes the kids education