Greetings!
I used to be a professional wedding photographer and invested in my Nikon D70. Love it, love it, love it. I now use it mostly for travel and to take shots to accompany my articles. It cost me about $1100 when I bought the whole package (lens, case, etc.) in 2004, but you can find it second hand for far less. Newer models in the Nikon family with higher pixels are cheaper and offer excellent quality.
I would recommend the cheaper, $100-200 models of any maker if you're not especially concerned about high quality, say, for local newspaper shots or for online jobs that pay you $40 an article+photo. However, for pubs asking for good quality -- or if you simply want high quality for your own portfolio -- definitely go for the SLR cameras from Nikon or Canon. They're relatively simple to use once you get the basics, and unless you're going into full-time professional photography, you don't even necessarily need to know all the bells and whistles that come with the equipment. As someone mentioned, though, it's always a good idea to take at least a basic digital photography class so you can learn how to make the most of your purchase.
I wouldn't necessarily recommend getting a huge memory card. I limit myself to 2GB cards, mostly because I'm concerned that if the card is corrupted for whatever reason, I lose a relatively small amount of shots vs. if I had, say, a 16GB card. That was a bigger problem when I was doing a wedding, of course, where I might have 500-700 shots in one night. If you back up your cards regularly, that might not be a problem.
And yes, definitely get the rechargeable batteries. Worth the expense!
Cheers,
Marjorie