a good primer on digital cameras can be found at kenrockwell.com and know that there will always be a debate until the end of time between Nikon and Cannon supremacy
it really comes down to the operator, use, and lens.
learning to the basics of photography and understanding how to use adjustments is what will give you great photos. A fancy camera will do no more to further your photography than a deluxe Wolf oven is giving you a better cake than a GE. It really depends on what you put in to the craft of it.
google 'food blog photography' or just 'how to photograph food' to get some ideas on how to set your camera and how to set a photo booth with natural light.
you also need to learn some basic photo editing tricks like working with color balances, sharpness and cropping. Very rarely will you see an awesome photo that is SOOC (straight out of camera)--almost everything is cropped and adjusted to make up for lighting and sharpness.