Dear Sri Royalrajesh1978
The link in Tamil given by Sri K Gopalan's seems to dwell only on how to prepare vettilai-paakku to take to Rameswaram, Kaasi, Prayaga and Gaya (use Kliplok bags) and how to pack akshathai to take home to grandchildren (use plastic sachets). Surprisingly he and it say nothing about good vaadhyar and accommodation at Kaashi which is what you wanted advice on.
I have been to Kaashi more than once, the last time in September 2014, when I visited also Prayaaga triveni sangam (a rewarding experience).
You can book accommodation in Kaashi online, after surfing the web and choosing what suits you and your parents. To avoid being ripped off, pay only a deposit initially, and pay he balance after inspecting what is offered. Ashrams are much cheaper than hotels and "residences" but amenities are minimal, and location not very near attractionas. Managers of ashrams are very helpful in advising where to go and what to do, and in arranging transport to places of interest, at reasonable prices.
Vaadyaars at all four places are rip-off specialists, especially the North Indian Hindi-speaking "paandaas". Daanams, dakshinas, extra dakshinas for unnecessary sankalppams, bringing in shishyas as assistants and demanding you pay them, rejecting veshti and paathrams and demanding money instead, are all parts of the game. Giving you "re-cycled" paathrams and vasthrams, and demanding prices for them as for new ones, is a popular racket.
Since you have another five months or so to go, have you considerfed reading up on the sankalppam and pithru shraaddham manthrams you will be performing/chanting at these four places? They are rather repetitive and easy to master. Same with pinda pradaanam. Practice makes perfect. Rehearse several times before you leave for Kaashi. You will be surprised how easy it really is. Take your note-book with you, and refer to it boldly. (As I did.)
The details of samvathsaram, ayanam, rithu, masya, paksham, thithi, and nakshathram will change. You can check your panjaangam and record them before you leave home, once you are sure of your actual dates in Kaashi and other places. You can also ask your local vaadhyaar to help you to do this.
Pre-determine what you intend to give the Braahmanas and vaadhyaars. Procure these at home and carry them with you. It will be far more expensive there. Stand firm if the Braahmanas and vaadhyar insist on money instead of daanam-items, or if they demand more items or more expensive items (e.g. silver pancha-paathram instead of brass). You are the kartha, the donor: they are the yaachakaas. Do not be deceived by any talk of "That is the custom." It is you who determine the custom, according to your family practice.
Allow your parents time to rest. Do not rush your activities.
Aasheervaathams and good luck.
S Narayanaswamy Uyer