About 150 staff and volunteers are working feverishly to set up, with much of the infrastructure needed for the biggest day on the war memorial's calendar put in place on Wednesday, ahead of last Thursday's full dress rehearsal.

Australian War Memorial assistant director Anne Bennie said it was predicted up to 50,000 people would come to the dawn service, with as many as 10,000 at the national service later in the morning.

She said with events of this size, the biggest challenge was getting everyone on the same page.

"The timings are the most challenging part, and the plan changes every year depending on the different elements we have in the ceremonies, who is marching and who the special guests are," Ms Bennie said.

This year, more than 3000 veterans will march at the national ceremony, led for the first time by the army apprentices, which will bring together a contingent of 803 members from across Australia.

Former Opposition leader Kim Beazley will deliver the formal commemorative address, with one of the last surviving members of the legendary Rats of Tobruk, 97-year-old Bob Semple, to give a special address.

The "rats" were a group of Allied troops who took their name from what German propagandists intended to be an insult about the underground tunnels they dug during the famous World War II Siege of Tobruk. Unfazed by the slur, the Allies turned it into a badge of honour.

"[The Rats of Tobruk] will all be gone soon, so to have Bob speak almost a generation on from his service is a real privilege," Ms Bennie said.

"His address will be very important for Australians to hear."

With most of the infrastructure, including video screens and 6600 chairs now in place, the days leading into Anzac Day will be dominated by meticulous scheduling, work on the War Memorial grounds, the preparation of wreaths, security briefings and transport arrangements.

Free park and ride services and shuttle buses will take people to and from the services, and depart from several bus stations across Canberra. People are encouraged to call 13 17 10 or visit Eventbrite to register for the buses, with parking at the War Memorial only available to a limited number of mobility impaired visitors.

From 4.30am on Anzac Day, representatives from each of the armed services will read excerpts from the letters and diaries of Australians who experienced war first-hand.

The dawn service then begins at 5.30am, and runs until 6am. The two-hour national ceremony starts at 10.30am.