I suggested in your "Sigma lens" thread about joining
POTN for research and learning more about the camera.
I wouldn't recommend the battery grip based on your (assumed) experience. They're more for hard core photographers, weddings, sports, where more grunt and battery life is important.
I
would recommend a spare battery or 2. Don't need to get the genuine Canon ones. There are 3rd party ones available at much lower prices.
Also recommend a flash - hot shoe, not horseshoe
But might be a little early for that for you. What is your experience? And what do you shoot mostly? What do you think you need/want a flash for?
Tripods - Manfrotto are good. I have one. Again, what do you think you need one for?
I'll PM you some websites/stores I use and recommend. Got in trouble last time I did similar for spamming
