I've been shooting Canon for years, so a rebel xti/xsi would be a good choice. You can get an xti for a great price now, and unless you're shooting billboards, you don't really need more than 8mp... in fact, if you can't get the shots you want done in 8mp, you should probably put the camera down.
Lenses are where you'll spend your money. I have a 40d, which I love, but most of the lenses I'm going to buy are going to be more expensive than the camera. Image Stabilization is a KEY factor to a good shot, especially with the ultrasonic motor to help you stay steady... but you pay for them. Read websites, steve's digicam review, hell, GOOGLE the exact model and see what real people have to say about them. Some people will hate and flame, some will praise without any knowledge (just like on here) but then you'll come across a few smart people who really know what they're talking about, and you can save a lot of money that way.
Ebay. You can buy a package, but make sure that ALL the lenses are good. Make sure they're OEM lenses... Stay away from offbrands. But sometimes they'll stick a shit lens in to drive the price up and make it look better... Say, for instance, you buy Canon, and the lens says "Image stabilization" but doesn't say IS-USM anywhere on it, avoid it. RESEARCH EVERYTHING.
Nikon offers a great camera, and their lower end (read: less expensive) cameras are great for someone who's entry level dslr. I'm not as familiar with their products, but I have lots of friends who shoot Nikon, and they like them.
Sony... They're expensive, but they have the best chips of any camera on the market. You generally pay 20% for the Sony brand, but you get a good camera, especially if you get a point-and-shoot. I've used the Alpha, and it was good, but I preferred my 40d over it.
You need to find out what you're looking for, and go for it. Be prepared to NOT have any money left in your pocket, and if you do, you'll be suprised... and you'll owe all of us on here a thank you.