Gear
Lenses If you're shooting with a DSLR you'll want to have at least a couple lens options. Two will probably work well for you unless you're a very serious hobbyist or semi-pro. My suggestion is a solid walk around lens such as a 50mm f/1.8 and a wide-ish zoom like the Digital Rebel XT kit lens 18-55m f/3.5-5.6. If you have a better wide zoom than the kit lens by all means use that but for the kind of tourist photos most people like to take on trips the kit lens will do fine. If shooting with a telephoto lens is a popular choice for you then maybe you'll take it instead of the wide angle zoom. It's up to you of course, just remember that you've got to carry and take care of everything you take. So take things you're going to use instead of things that you maybe possibly will use but will instead probably just end up taking up space in your bag.

Camera Bag To store your camera body and lenses you're going to need a camera bag. Look for a bag that is padded and has a padded strap or straps. Make sure the bag is comfortable since it's going to be your best friend while you travel.

A couple safety tips regarding bags:

• Make sure the strap of your bag goes across your body/around your neck, not just over your shoulder like a purse. Potential muggers love to see a bag just dangling over someone's shoulder. Running from behind they'll just grab the strap off your shoulder, your arm will be pulled forward and the bag will just slip off in the mugger's hands as he runs away.
  
• Find a bag that doesn't scream "I'm a camera bag with expensive gear. Please steal me."

Misc. Supplies Universal essentials that you'll want your bag to be stocked with.

• Lens cloth: Lenses do get dirty
  
• Memory cards: Over estimate what you think you'll need. Number your cards and use them in sequence. You'll know which cards are empty, which cards are full and generally what part of the trip you used each card during. Forbid anything happen to any of your cards but if it does and you've kept track you'll know exactly what you've lost.

  Store your full memory cards away from your camera (say locked up back in your hotel room). That way if anything does happen to your camera bag you won't have lost every single image from your trip.

• Backup battery & Charger: DSLRs don't run off AA batteries and grocery stores don't sell the battery packs required. So make sure you've taken care to have plenty of power on your trip.

Pre-Trip Prep
With all your gear gathered in one place (namely your bag) it's time to test it all out. Test your camera body, shoot some sample shots with each lens, test your memory cards, plug in the battery charger. Make sure everything is working exactly the way it should be. How much would it suck to get to France or the Grand Canyon or the beach only to find out that your battery charger won't work and you only brought one battery?

Shooting Tips
- Early morning and early evening are your friends. Not only do you get the best light but you also get the opportunity to shoot with fewer people around. Less people equals better composition options.

- Go beyond the expected tourist shots. I can Photoshop you into the Eiffel tower; go for more. Document what the area is really like, what your specific trip is really like. We're going to believe you when you tell us you went to France. You don't have to show us the Eiffel tower or the outside of Notre Dame. Instead show us your favorite cafe or the people working the patisserie you found heavenly.

- Use your surroundings. It's not likely you'll be traveling with a tripod so for low-light situations look around and figure out what you can use. Benches, walls, door frames you can brace yourself against can all be used to reduce camera shake in low light/slow shutter speed situations.