In Khartoum, you will need to register as a tourist at the airport police station. You only need to register if you spend more than 3 days in Sudan. If you are sure you will spend more than 3 days, you may also pay upon entry at the border.
Registration will cost you $50. Yes, that is $50 over and above the fee you paid to get the visa.
When you arrive at the Sudanese border, please be aware nobody speaks English but this can actually work to your advantage. When I arrived, the officials were outside in the heat drinking coffee under a tree, that meant sitting for what felt like forever waiting for assistance. Eventually I ran out of patience,if you speak English they will help you faster because they actually want to get rid of you.
What you really need to be aware of is that Sudan national language is Arabic, so none of the officials that try to help you do not speak English. If you smile, it goes pretty fast.
From Khartoum you can take a bus to Wadi Halfa. This bus will be a 12 hour journey, it will cost you 150SDP. Whatever you do, do not take a bus from Khartoum on a Thursday. Sudanese borders do not open on Friday so you will be stuck in Half a for 2 nights and you honestly do not want to subject your body to the state of hotels in this little border town.
You will have to spend a night in Halfa because the buses just delay for no reason so that by the time they arrive in Halfa from Khartoum, the border is closed and you have to spend a night at the motels.
In the morning you can take a bus to Cairo or to Aswan. The bus goes to Cairo but you can get off in Aswan. That is the route I opted for and that is what most other travelers do as well. The drive from Halfa to the border is 30minutes. There will be dozen other busses filled with passengers because all buses move at the same time. It will take just over 4 hours to go through the Sudanese border. This border is still new, has only been in operation for 6 months. Before that everyone traveled to Aswan by the ferry that only traveled from Halfa once a week.
Please note you will need to pay another 120 SDP to be stamped out of Sudan.
It took over 6 hours to go through the Egyptian border. My passport was confiscated as they weren't sure what I was doing there. Never mind my valid visa. Apparently they don't see Africans often at their border. Don't ask me what all those Sudanese people are if not African. I actually found this insulting. Eventually an official wanted a bribe to let me into the country and of cos I was not willing. I eventually got my passport and we proceeded.
Another 30 minute drive to the ferry. The ferry takes up to 10 buses. It's a 1.5hr journey on lake Nasser into Abu Simbel. From Abu Simbel, the bus will drive another 3 hours to Aswan, this is where I gott off and found a hotel. Wanted to spend a day in this Nubian town. From Aswan you will need a train to Cairo.
Please note, the train does not sell 1st and 2nd class tickets to foreigners. Tourists can only buy the $100 tickets. The 1st class tickets on the train are 170EGP, including dinner.
After struggling to get that ticket not knowing better, I went back to my cab driver and asked him to buy me a ticket. After I was told all the tickets are sold out, he came back with a ticket 10 minutes later.
So get a local to buy your ticket. They can't turn you back at the station on your travel time because your ticket is paid for.
For a country that is struggling for tourism, Egyptian officials really know how to make someone feel unwelcome.