For more information than you can possibly use, see
http://dpreview.com
Added - Some of the following doesn't apply to you but I don't know what you know so I don't know what to leave out.
The D50 is a digital SLR (DSLR). All of the current DSLRs have more photo quality than most of us will ever be able to take advantage of.
Heck, the point and shoots are now getting really good
http://rickleephoto.blogspot.com/2007/04/studio-photography.html and I've heard of a camera phone that is approaching them.
This is important because any camera that you have with you is better than one that is not with you.
There are cases that let you use SLRs underwater but they're expensive. There are water-resistant point and shoots (enough for casual snorkelling). Water-tight cases for the point and shoots are a lot cheaper but they are model specific. (Water absorbs red so you may want to color adjust for underwater. Some cameras try to do this for you - see below - or you can photoshop it later.)
Seriously consider image stabilization (IS) - you'll get more good pictures. Most newer mid-range and better point and shoots have it these days. (Some/all Sony SLRs have IS in the camera body. Canon&Nikon put it in the lens and some lens don't have it. In the body means that you have IS regardless of lens. However, Canon and Nikon have a much wider variety of lens, they're cheaper used, and some of them are beyond superb if you're into that sort of thing.)
Ignore digital zoom - you can get that when editing with the computer and it's never as good as optical. Unless you go with a DSLR, you want "enough" optical zoom. However, you won't see (good) 10x in a small camera. Too little zoom means that you get to edit or miss the shot.
If you're just taking pictures of small groups of people within 20 feet, 3x zoom will do. They're not very good for scenery and they're not very good if you're trying to take pictures of the shows, but they're almost impossible to shoot anyway because of the extreme dynamic range. (You can get good pictures of spotlighted things, but everything else will be black or you can get good pictures of the rest, but the spotlighted things will be all white. If you want both, you have to combine images.)
For DSLRs, you get 10x zoom range by switching lens or by spending a lot of money on a very heavy lens. (No, they don't solve the show problem. The good pictures that they use for advertising are staged with lighting designed for photography.)
If you've used a digital camera that you like, there's some chance that another camera from same family. (Canon's point&shoots are more like one another than they are like the DSLRs and I assume that the same is true of Nikon, Sony, et al.)
The big advantage of the DSLRs over point and shoots is the size of the sensor. Bigger can be way better. There are point and shoots with more "megapixels" than the D50, but the D50 gets more information out of each pixel. It also does a better job with less light. (Most point and shoots top out at 400 or maybe 800 ISO. The D50 almost certainly goes to 1600. Remember high-speed film for taking pictures at night? That was 1600 or faster.)
Some cameras that don't have interchangeable lens are roughly the same size as DSLRs. They have bigger sensors than point and shoots and some have decent 10-12x optical zoom range. These are good things.
FWIW - Char has the Canon XT (SLR also). It's a nice size and lets her use the lens that she bought for her canon 35mm. (If you own a couple of lens that you like, switching to another brand is very expensive.) The XTi (newest model) has a self-cleaning sensor. (When you switch lens, you can get dust on the sensor.) I have a 20d (also canon, because I want to use her lens). It's the same size as typical 35mm SLRs (remember them?) but its big advantage is 3200. Yes, it's more grainy than 1600 but when the alternative is no picture....
We also have a canon point and shoot that we also use underwater. It's older, so no IS, but it does color-adjust in the camera for underwater. (Even if you're going to photoshop, that provides more data for photoshop to work with AND it means that you don't have to photoshop as often. I wish that our DSLRs had that option because I have a lot of photos taken from a submarine that require photoshoping.)
) I carry a fishing scale that is actually pretty accurate for on the fly. Just so people are aware - most of the WDW resorts have baggage scales now since you can check in at the resort. I would hope that the hotels in Europe might also - even if they are in Kilos (just multiply by 2.2 to get the pounds)
My packing avoidance tactics this morning were 
that she (and you all) will feel better soon.
Great explanations!
I know the loss of a bunny hardly compares to the losses others of you have gone through recently.
Good wishes your way, and yes, letting her cope in her own way is probably the best idea. I can't even stand the thought of having to put my dog down. Sometimes at work during a massage I have a breif moment of thought about it, as I had to do it to my cat some time back, and I cry just at the thought. 
