I did some photography in high school (ages ago), then only picked it up again a couple years ago. I did have a couple different point and shoot cameras in the years prior to that but never really liked them that much. I much preferred the DSLR because I could control a lot more of the settings and I actually like the feel of a DSLR camera as opposed to the point and shoot. I'm from a non-artistic background and my job is a technical one (programming) but I felt I needed a hobby to feed my creative urges.
I'm far from an expert so take any of my advice with a grain of salt.
1. What is a good beginning camera and any beginning equipment you'd recommend and why?
I personally think that whatever brand you choose, you should get a package with a couple lenses - most brands will offer a combo with an 18-55mm and a 70-200mm lens, which is a good mix. This will give you a wide lens to shoot landscapes as well as a zoom lens to shoot wildlife. A sturdy tripod, if you don't have one already, would be bonus when shooting wildlife or shooting long exposure water shots. I would consider that (camera, wide lens, zoom lens, tripod) the setup that will give you the equipment to do most of the shots you'll want to do.
If you do low light shooting, also consider a 50mm f1.8 lens. Regardless of camera brand, there's usually a 50mm f1.4 lens offered as well. However, the f1.4 is typically 2-3 times the cost of the f1.8. If you get everything new, you could probably get the 2 lens kit, the tripod, and low light lens for under $1000.
If you take photos of people, especially in indoor settings, you'll probably want a dedicated flash (and a diffuser if there isn't one built into the flash). Depending on the flash, the can set you back $100 or more, depending on how powerful you need it and what kind of features you want.
Before you pick up a DSLR and lens combo, it's important to figure out what brand you want. If you continue with photography and get more into it, you'll probably be sticking with one brand, as you'll be adding lenses and equipment. The lenses will typically last a lot longer than the camera body (case in point, I'm currently using a couple of 20+ year old Minolta lenses with my 2 year old Sony camera). If you upgrade the camera body to one of the same brand, the lenses and most of the other equipment will still work but if you switch camera brands, you'll essentially be starting over. If you want to buy used lenses to save a bit of money, you'll want to look at the market for used lenses and compare what's available.
3. Any books on photography or books of photography you'd recommend to a beginner?
I haven't read much in way of photography books but I really liked "The Photographer's Eye: Composition and Design for Better Digital Photos" by Michael Freeman.
4. About how much should I expect to invest in photography? I love nature photography and photography of places we travel. I don't see myself being a wedding photographer or anything like that.
It really depends on what you like to do. The above equipment I mentioned (for about $1000) will let you do a lot of different types of shots. If you want to get more specialized, then you could easily spend hundreds or thousands more.
Example: Macro photography
Option 1 - extension tubes. Cheap ($5-$10) but generally doesn't let you adjust the aperture and you lose autofocus as well.
Option 2 - extension tubes, manual lenses, and maybe a lens adapter. If your camera lens mount doesn't accept older manual lenses, you'll need the lens adapter. This setup is similar to option 1 but lets you adjust the aperture. The lenses can usually be used for cheap.
Option 3 - Bellows system with some manual lenses, possibly a lens adapter as well. This setup lets you do extreme close ups and allows you to control aperture as well as giving you something analogous to a zoom. But it requires more setup for the shot and you still don't have autofocus. Cost $50-$100, depending on what lenses you get.
Option 4 - Macro lens. Expensive (usually $500+). All the bells and whistles but at a much higher cost than the options.
Optional equipment: Ring light - the subject may be too close to the lens for the flash. Focusing rails allow you make adjustments (left/right and/or forward/back - one rail for one dimension, two rails for two dimensions) without moving the tripod.
For sports photography or long distance wild life action shots, you could get something like a 70-200mm f2.8 lens for about $2000-$2500 or a more expensive 400mm f2.8 lens for about $10000.
So, it really depends what you want to do and what you're willing to spend.
6. What film do you prefer and why? Do you develop your own film or do you do everything digital?
I prefer digital because with the way I shoot, only about 1% of my shots are anywhere close to good. I'd go broke trying to do it with film.
There's an interesting contest in my home city that makes good use of film. It's called the 12x12 Vancouver Photo Marathon (that's Vancouver, BC, Canada - not Vancouver, Washington). On the day of the competition, the entrants are given a roll of film with 12 exposures. They must take a photo each hour. At the top of every hour, they have to be at the contest base where they will receive the theme for hour. They then must go out, take the single shot, and return within an hour to receive the next theme. The photos are judged as a set so all your photos must turn out to be in the running for a prize. If you want to challenge yourself and simulate having film, you could probably attempt something like this on your own.
7. Can you maybe post a favorite picture or pictures you've taken? Do you have any photos from when you were a beginner? I'd love to see them. Tell me why you love them!
Here's a few shots for the first DU contest I entered ("Green" in August 2009)
This was my contest entry. It placed 4th in the finals. (Got my ass kicked in the next few contests so it was definitely beginner's luck to place that high.) In case you're curious, it was taken at an aquarium. I pressed the lens right up to the glass to reduce the reflections. Lighting was good so I didn't use the flash.
Here's one I didn't enter but like. It was one of my first attempts at shooting water drops.
Here's another I didn't enter. Not entirely sure why I like it, though.
I'll leave you with a suggestion. For the monthly DU contests, try to get a photo you think would be worth submitting. Even if you don't enter the contest, it'll give you a reason to take photos of things you normally wouldn't think of photographing.