To start with, add:
1. Tripod
2. Case/Bag
Then you should look into this:
Lenses - The lens that comes with the camera should be the 18-55mm one. Don't expect to take any good up close action drift shots with that. Look into a 75-300mm lens instead. In most cases you'll be good with that. Also when shopping for lenses, you should familiarize yourself with some of the terms used to showcase the features they come with.
USM: Ultra-Sonic Motor. Most Canon lenses I've seen come with this. Makes the lens quieter when auto-focusing.
IS: Image Stabilizer. More expensive Canon lenses have this. Helps you avoid getting blurry shots when shooting in a low-shutter speed.
L: This is Canon's L series lenses. To put it in automotive terms, this is the Lexus of lenses.
4-5.6: You'll find a number like that next to the focal length specs. That tells you the aperture range of the lens. Using my lens as an example, it's 75-300mm with 4-5.6 aperture. @ 75mm, the lowest aperture setting I can use is 4. @ 300mm, the lowest aperture setting I can use is 5.6. A low aperture number can help give your shots that blur you've seen in pictures. But, there are lenses out there that just have 1 set aperture. Meaning @ 300mm, I can have an aperture setting of 4 from the lowest focal length, to the highest.
Memory cards - Not all cards are the same. SanDisk offers memory cards that write at different speeds. For still shots you should be fine with their regular memory card. If you want to do multiple continuous shots, look into their Ultra II, Extreme III, and Extreme IV cards.