Clothing/Shoes/Weather Gear: Jacket should be must-take thing to the salt mine. Temperature inside salt mine is pnly about +13 degress (so, imagine, when you go to it from outside +30 temperature). What is more, in some places where are no condition, salt is melting and dropping down. Later this salt cristalise and it is white dots on clothes (not dangerous, but just to say it).
We have 2 km to walk through the mine ! Wear comfortable shoes. The temperature in the mine is 14 Deg. Celcius. In Summer, tour starts every 5 minutes or so but in winter tours depart every half an hour to an hour when enough people have turn up.
Toiletries and Medical Supplies: Yes, it's better you go to ease yourself first before descending to the underground mine.
Photo Equipment: Taking photos can be done in the underground, so make sure you bring enough films & hold your camera really still because some areas are dark & you get blurry photos !