Bottom line is this : both Nikon and Canon make excellent entry level cameras in the DSLR market. Either brand, even models that are 2 or 4 years old are great. People are really spoiled nowadays. My first "real" SLR was a Nikon EM, great camera, but compared to what you get today for the same money (taking inflation into account), seriously, I cannot see how you would go wrong.
My main concern is that the electronics in these new cameras can be easily damaged by rain, dropping the camera,etc. if you are buying a used camera and you do not know how well the previous owner looked after the camera, then what happens when it stops working? Because of that, I highly recommend a refurbished camera directly from Nikon or Canon, or from a reputable dealer. Refurbished cameras usually come with some kind of warranty, anything from 30 days to one year, depending on how expensive the camera is.
The basic kit lenses from either brand are not bad at all optically, especially for the money, but mechanically they can break easily. For example, the all plastic mount on the Nikon 18-55mm seems to break all the time,seen myself more than once. Either brand, a basic 35mm prime lens would likely be pretty bullet proof in terms of ease of use and long term durability.
One last thing buying used, make sure the battery is new or in good shape, and a brand name battery. My experience, the 3rd party brands only seems to last a year then they simply do not hold a charge as long as the brand name batteries do.