Here are a few points that you can consider when choosing your first DSLR
1) What is more important to you? Image quality or video quality?
2) Considering your current budget and experience level, what does each camera manufacturer has to offer?
3) Consider the possibilities of upgrading in the near future. If what the manufacturers offer at the moment are of importance to you. then chances are they may offer upgrades to it in, say, two or three years down the line.
4) What kind of lenses do you like to keep in your arsenal. And does the manufacturer offer those lenses?
To be completely honest, you will be better off choosing either one of the brands. Since both the brands are continuously competing with each other in producing better cameras than the other, you can never go wrong, no matter which brand you choose. Just make sure that you stick to a particular brand as it will make purchasing lenses, accessories and other future upgrades much easier. It is not an easy choice, but is not a tough one either. Consider websites like dpreview.com to compare various brands side by side. It will help you clearly understand what each camera has to offer and how is it different from the other.