Hold It in Your Hand
While you may end up buying your DSLR online from an online retailer, you may want to consider going to a store and actually handling the camera to see how it fits your hand size and how accessing the controls match up to you.
DSLRs range in physical size from quite compact to fairly large. If you are someone with small hands, some of the larger ones may actually be uncomfortable for you to use or vice versa if you have large hands. So try them out first - either at a big box store or even preferably at your local camera store. But do me a favor, if you go to your local camera store, which can be a wealth of knowledge in helping you decide on the right camera for you, buy it there too. Don't take their advice for free and buy elsewhere or that place may soon not exist.
If you do buy online, just remember the old adage: if it sounds too good to be true, it is too good to be true. Meaning if you find a place whose price is far below what everyone else is selling it for, be very wary and check them out before you hand over the credit card.
Many are not selling new in a box, some without warranty, some without all the accessories that come standard and they will try to sell them back to you separately. Some, you just plain will never see a box arrive at your door. So think twice before you buy what seems to be an incredible deal.
My recommendation for who love shopping online, is buying from most trusted online marketplace as Amazon.com, and also look if who put the product or bundle in Amazon is trusted seller or not.