new camera, but which?

hi,
first of all hi to all of you since im new here.
i recently started using my sisters digi cam (powershot S400) and just loved it. Ive loved photography since i was little and love how shots come out with SLR cameras. ive been thinking if wether of not to get one, since its a big investment. what do you think? keep in mind im anewb, not a good photographer. most of my pics suck. i was thinking of the Canon EOS Rebel. ive heard nothing but good outcomes of it or should i just start out with a good point and shoot camera? maybe the S500?