Definitely pack warm. We were there in mid September and I don't think we ever slid out of our jackets. I will admit we are sun loving Australians but it was cold and overcast most of the time. We didn't experience rain but I would say judging by the gorgeous gardens it is a regular occurence.
Photo Equipment: Of course pack a camera although there are some attractions that you pay an entry fee and they won't let you take pictures. We noticed this a fair bit in Austria and Germany.
Luggage and bags:
I always prefer roll on luggage as it is most convenient luggage to travel around in Europe where you walk to your hotel to and from public transport and also all the airports are well connected to public transport.
Clothing/Shoes/Weather Gear: If visting Salzburg most defintly pack a Sweater / jacket in any season. The reason for this is the Salzburg is located on the the river that flows thru town.... the cold drift from the river really cools the town and you can get cold by the evening.
Toiletries and Medical Supplies: Usual necessities that you would carry on any trip.
Photo Equipment: Salzburg is perfectly safe and you can carry all the equipment that you own with absolutely no isses.
Luggage and bags:
Remember if you are going to travel via train(and doing so is quite comfortable and affordable), to bring two or three small bags that can be carried and loaded quickly. German / Austrian rail run on the most efficient and unforgiving schedule. It is always easier to toss a small bag to a helping hand to get on board before the train departs, and Most trunks in European autos are not quite as large US, so smaller bags can be manipulated as needed.
Clothing/Shoes/Weather Gear: The weather throughtout all of Europe can change on a dime, especially in the Summer. I've seen from 42 - 98 (F) degrees in June. Make sure you bring light to medium clothing to layer, so that you are not strapped with a heavy coat that you must carry even if it never gets cold. A medium windbreaker should be sufficient on even cooler days when paired with an undershirt, dress shirt and sweater.
Toiletries and Medical Supplies: Powdered Gatorade packets and Peppermint Lifesavers are a highly mobile, simple remedy to many gastric problems you may have in traveling. Gatorade is wonderful for those times you cannot hold anything else down, but you have to keep going (The show must go on, especially on a tour package).
Luggage and bags:
Take a comfortable backpack with not too much weight... If you stay in the hostel we did then you will need to do a bit of walking to get there...
Clothing/Shoes/Weather Gear: Good walking shoes are a must...you will probably walk almost everywhere you go in Salzburg...
Photo Equipment: Make sure you take a lot of film for the many photos you will want to take. A zoom lens also comes in handy for getting to those 'hard to reach' places...
Clothing/Shoes/Weather Gear: During winter, make sure you have warm clothes and a waterproof jacket. Gloves are a good idea, as are hats. A pair of sturdy, waterproof shoes or boots for walking around in are also a good idea, especially if you plan to wander round the Kapuzinberg and the Mönschberg.
If you're looking to do some outdoor adventuring, be certain to pack some good quality hiking shoes (insulated, waterproof, and good soles). The austrian alps can wear out your shoes quickly. As far as clothing goes, It never gets too hot nor too cold in Austria. In the winter, always be prepared for snow and definitely for rain. During the summer, bring summer stuff along but also pack some warm clothing for those chilly evenings.
Photo Equipment: Don't forget your camera. There are sooooo many great things to capture on film. A camera is a must!
Miscellaneous: Make sure to pack an appropriate converter for electrical equipment. Austria uses a different power outlet and voltage than we do. Contact your nearest travel shop for help.
Take the most comfortable walking shoes you can find!!! And take a break when you need to...there are little plazas filled with coffeeshops and statues every time you turn a corner.
Photo Equipment: This city is a photographer's dream.