Things to look for:
1) Batteries.
Try to avoid proprietary batteries. They tend to be on the expensive side (this IS the BB!!). Use NiMh (nickle metal hydride) or Lithium ION (more $$ but better than NiMh. Avoid Alkalines. Digital cameras are tough on batteries and Alkalines don't last very long. The camera I bought uses "AA" size. It's a very common size and can be found almost anywhere.
I have 5 sets of batteries and two chargers plus a rechargeable (lasts all day) battery pack.
2) Memory cards:
It's really a personal choice since you don't have any now. There are about 5 different types. The newest ones are really small (postage stamp size). Try to determine your picture taking habits when you use film. Since taking pictures with a digital incurs no processing or printing (or not as much printing) costs, shoot as many as you like. You can always delete the duds!
I tend to take several shots of the same thing from different angles or using different settings. This means I shoot a lot of pics.
On the last two trips to WDW (a week trip) I shoot about 1000 pics on each trip.
You'll need to think about what to do if you run out of memory cards. I take my laptop with me and download them each (or every other) night. It's also nice to be able to email pics back to family and friends. If you don't have any way of storing the pics other than the memory cards themselves, you'll need to have plenty on hand.
Look at the specs of the camera you get to see the estimated number of pics per card. The cards come in sizes like 32meg, 64meg all the way up to 512meg. The larger cards tend to be disproportionately more expensive than the smaller ones.
The 128meg and 256meg cards are about the best deal right now.
My 2.1 megapixel camera puts about 45 pics on a 64 meg card and about 90 on a 128 meg card. However, depending on the subject you're shooting, you could get a lot more per cards. For example, you can get more dark room with low lighting pics on a card than being outside in bright daylight.
3) ZOOOOOOOOOOOM!
There are two kinds of zoom. Optical and digital. Avoid any camera that has only digital zoom. You'll probably be disappointed in the results. Look for a camera that has at least a 3X (or more) OPTICAL zoom. This will make for better pictures. Nobody likes to see an ant size person in the middle of a picture.
4) MEGAPIXELS
The more the better. But it also depends on what you'll do with the pics. The higher megapixel cameras tend to take better pics than the lower ones but they also produce larger files. This means less pics per memory card. A 2 to 4 megapixel camera would meet most peoples needs for pretty much anything they wanted to do with the pics (printing, email, online album, etc)
Also, to get the best possible pics while maximizing the amount of pics you can put on a memory card, read the owners manual and set the camera to the highest resolution and best image quality (might be called compression or SHQ, HQ, Fine, Super Fine). DO NOT use the TIFF setting (don't worry about what it is for right now, just don't use it).
As you can see, the initial costs can be high but it's a one time up front expense. If you shop around you can get good deals on batteries and memory cards. If you're not afraid to buy something on the Internet, you can usually get MUCH better deals on cameras there. Just know what you want and buy from a reputable place (checkout
www.resellerratings.com to see how a seller rates)
I have not shot one roll of film since buying my digital camera 2 1/2 years ago.
For reviews and sample pics of various different cameras as well as dicussion forums, check out
www.dpreview.com
Checkout my digital pics from our 2001 WDW trip at
www.pbase.com/emmagata/disney_2001
Good luck!