Ok, here is my 2 cents:
There are 3-4 day trips and one week itineraries. I find one week more effective due to the overheads of flying & travel times, no-fly time due to N2 loading. From memory, I flew early friday morning with Egypt Air to Hurghada via Cairo. (There is no direct flight from Dubai to Hurghada or Sharm or Dahab or Port Ghalib, which is about 3 or 4 hours drive from Hurghada). The operators provide pick-up and drop off sevice form the airport so you do not have to worry about the transportation. If your boat starts or finishes at port Ghalib, the companies arrange pick-up & drop-off from Hurghada airport.
The boats usually leave on saturday morning and come back thursday afternoon. So when you arrive on friday, the boat is under preparation for the next trip. You can drop your bag to the boat and go enjoy the rest of the day until the night but you sleep on the boat on friday night, also do your check in as well. If you arrive earlier than others, you might push your luck to get a cabin of your choice.
The boat leaves on saturday morning around 9-10 and you would have a test dive within an hour or two. This helps you to be perfectly ready for the coming dives and also let the dive masters to assess your skills without explicitly saying. After the lunch you would have your second dive and maybe a night dive. Then usually the boat starts to make long way until very late night to cover the distance they need to go.
A typical day starts at 6:30 wake up, 7:00 briefing and first dive, then you have breakfast, around 11 or so the second dive followed by lunch. Then slightly longer interval then about 3 or so the third dive. Between the dives, the boat moves to the next site, so every dive is usually different sites. If there is a night dive, you jump to the water slightly after the sun set. Then you have dinner around 8-8:30. And the boat moves longer distance at night for the morning site.
On thursday, you may finish with two dives or highly unlikely three. The boat moors back to the port in the afternoon to be ready for the next trip. They may let you to stay in a hotel for that night or sleep on the boat. Then they arrange the transports for the airport either friday morning or late thursday nights.
Some of the itineraries do not allow night dives or only one or two due to the sea conditions of the sites, like Deadalus etc.
Since it is quite an intense activity, I suggest to use Nitrox. If you are not certified, you can do it during the trip as I did. You just dive first day Air and then switch to Nitrox the second day. I believe all the boats have Nitrox capability but better to check before you pay.
You can get these details more correct once you select your tour or during the booking process.
There are quite large number of companies doing trips, some are based on the company country setup or main target so they get to have more Germans, British or Russans, etc.
I was not sure and did not have anyone to ask so I was cautious in my first tour, after doing some search I chose https://www.emperordivers.com/
. I was quite happy with them and then i went again with them for the second time. I could not find the right match for the third trip and I went with https://www.blueotwo.com/Home
company through the broker https://www.liveaboard.com/
If I go again, I would chose Emperor. But like anything else, it is the people make it shine. The other good thing about the liveaboards is that they go to the popular sites before the day trippers and try to arrange the dive times not at the same time as the other groups. In crowded times, you may even lose your group if you do not pay attention.
I was very much impressed with the food offered on the boat. The cooks have such a small space to work yet they create very nice meals. I would also give a higher mark to Emperor on this too.
Some dives can be challenging with strong currents and you need to be comfortable and competent as they may require negative entry.
I suggest the first time itinerary as reefs and wrecks, which gives you very nice mix as mentioned in the name. Southern part of Hurghada is also very nice for beautiful morning sun rays in caves too. Leave the outer far site for your later trips since I am sure you want to go again.