Both of them are very good for you. I only use the canon but don't mean either canon is better than Nikon or Nikon is better than canon, because my first photo teacher use the canon.
For the 550D is as same as the Rebel T2i in USA, and I usually recommend the canon brand lens. You can get the canon EF 24-105mm f4L for $1050 http://www.amazon.com/dp/B000AZ57M6/ref=asc_df_B000AZ57M62099806?smid=ATVPDKIKX0DER&tag=pgtvs-252-47-20&linkCode=asn&creative=395097&creativeASIN=B000AZ57M6to
start. Then you can add other lens such as more wide angle lens (< 24mm) or telephoto lens.
The D3200 is also a good camera, and usually Nikon is more expensive than the canon. If you take the d3200, then 24-120 mm f/4 lens is the good one. In here (USA) it will cost $1300.
By the way don't buy the Kit lens that come w/ the camera, like 550D w/ 18-55mm or 18-135mm. Also don't buy the cheaper the third party lenses, if you buy just get the few good 3rd party lens like some of them: sigma 17-70mm F2.8-4 DC macro, Tamron 17-50mm F2.8 XR Di II.
And go to the web to read a lot to learn how to control and setting the camera too. When after you get the camera read the manual completely and go out to shot a lot, and take a look the pictures you took and compare w/ other to see what is different. If there is the different and find out how to improve.
Last thing go out and take a lot the pictures. Like NiKorr said you need tripod, external flash, and some filter too, but don't put the filter on the lens all the time.