While booking you needs to fill one Photo proof ID with number, it may be PAN card, Driving license, Passport, voter ID. The same photo proof ID original you need to carry while Darshnam time, then only they will allow for darshnam. If you are booking five tickets you need to give their name and age (below 12yrs its free), and need to upload all the five devotes photo, the photo size should be below 10kb, check you photo size before loading, if its more than 10kb go to google.com and find the free image size reducer website and resize to below 10kb.
Once you upload the entire photo you can get a payment gat way (for E-Sudarsanam it cost 50 Rupees for each person), here you can pay via credit or debit card. I done my payment via city bank Indian account, I am not sure it will accept international cards or not, better use Indian bank cards. Once the payment had done you can get a ticket copy with the photo of devotees. Just take a printout, also ticket soft copy will mail to your mail id the one you enter at register time. Take minimum two copy of the ticket while darshnan time one for entry other for Laudu.
Also TTD introduced online facilities for e-seva tickets, e-Accommodation, e-Sudarsanam and e-Hundi. Make a use of it and make your trip comfort.
Pass this information to your friends and relatives.