The main bus terminal is a couple of kilometres out of the centre and its worth taking a taxi to it. There are good connection to Hurgarda, Suez and Cairo.
Cairo can easy be reached by train. There are several rolling to the capital throughout the day.
Its a battle for surviving to get in or out 3rd class wagons.
I´ve seen people exiting through windows because all doors were blocked by crowds fighting to get in!
Better spend some more money and travel first or second class.
Are you a cargo-boat? No? Then you are not allowed to travel on the Suez Canal... however there's a way to cheat a little bit... there's a small passenger and car ferry in Ismailia, that drives you from one side of the canal to the other... and yes, you are crossing it while huge-cargo boats are passing, too.
It's really worth it!