Congratuations! You will have a lot of fun with your new camera. As Frank mentions, digital is great because you can experiment and shoot to your heart's content without worrying about the cost of film and processing, and of course you can see what you're doing all the way... No more hoping-for-the-best and holding your breath as you develop the roll of film and stick it under the enlarger only to see that, oops, you didn't get what you'd intended.... No more peering at the slide and sticking it into the projector only to see that, oops, you missed the mark.... No more cumbersome Polaroid backs on medium-format or large-format cameras in an attempt to get a preview of what you're trying to shoot before using expensive film.... Shooting with a digital camera has wiped all those problems away.
Tips: Get more than one memory card. You will be shooting a lot and there may be times when you don't have time to download into the computer, especially if you're out for an afternoon of shooting somewhere. Get the largest size memory cards you can afford, too, because you can never have too much memory. Also get a spare battery for the camera. Even though battery life is pretty good on these things, it is always advisable to have a spare at hand, especially when out shooting for a long time or when using flash extensively.
If you don't already have a good image editing program, take a look at Photoshop Elements, which has many of the same features as its more expensive big brother Photoshop for significantly less cost. I think PSE is now around $100, whereas of course PS CS2 is more like $650-700.00. I think while PSE 4 is available for the PC we Mac users are still in v.3, but I've been told that there is really little difference between the two versions.
Find yourself a good camera bag to tote your D50 and lens(es) around in while you're out and about, and also for safekeeping at home. Dust is the DSLR's enemy and keeping your camera and lens(es) free from it is imperative unless you want to spend a lot of time blowing dust bunnies off your sensor. Eventually you'll want to get a Giotto Rocket Blower but unless you're changing lenses a lot, especially under unfavorable conditions, you shouldn't need to worry about cleaning the sensor for a while. I had to get out the blower for the first time a couple of days ago when suddenly a nasty big old dust bunny appeared in my view as I was getting ready to shoot after having switched lenses for the third time during the session. A couple of puffs with the Giotto and that sucker was gone and I was back to business.
This next tip is a hard one. Try not to succumb to the infamous "lens lust disorder" which usually strikes most of us who have and use SLRs and DSLRs. It's insidious and sneaks up on you.... You start out with one lens and then you think, "gee, if I had a [fill-in-the-blank] lens, I could do this or that...." and then you buy that lens. Next thing you know you're thinking, "well, gee, if I had a [fill-in-the-blank] lens, too, I could do...." and you're hooked. The beauty of shooting with a DSLR is the flexibility that comes with being able to use interchangeable lenses. The havoc this can wreak on one's pocketbook can also accompany owning a DSLR. One nice thing, though, is that if you need a particular lens for a specific occasion, if you're in a large city or suburbs in a large urban area, you can rent the lens for a day or weekend. If you have friends who have the same brand of camera it's fun to swap lenses while shooting together, especially if the friends have a greater variety in lenses than you do.
In the meantime, work with the lens(es) you've got, really get to know what they'll do for you and how you can optimize results from them, and also get a sense of what you like to shoot. Only THEN start thinking about what other lenses might fill specific needs...
"Lens Lust Disorder" is fortunately not fatal, but it can be chronic. Fortunately there's no hurry to "cure" it, one can take one's time in accumulating and using lenses through the years....
OK, editing to add a summary of everything I wrote above:
1. Get more than one memory card.
2. Get as much memory on each card as you can afford.
3. Get a spare battery for the camera.
4. Get a good image editing program such as Photoshop or Photoshop Elements. iPhoto will do in a pinch but it really isn't as flexible as the other programs designed for editing.
5. Get a good camera bag for keeping the camera and lens(es) safe at home and also for carrying when you're out and about.
6. Get a Giotto Rocket blower for getting those pesky dust bunnies off your sensor. Yes, it WILL happen eventually.
7. Work extensively with the lens(es) you've got before allowing yourself to succumb to "Lens Lust Disorder." Pay attention to what you like to shoot the most; this will help in deciding what your next lens purchase should be.
In a nutshell, just have fun with that new camera and get out there and SHOOT!!!
