A lot of the procedure depends on how well the engine was shut down previously. Let's assume that was done properly...
After checking water glass levels, and assuming an oil fired engine (rather than coal) a large wad of waste (looks like a mass of used threads) is soaked in fuel oil and placed just inside the firebox door on a ledge of fire brick. The oily waste is then ignited, usually by a fusee (looks like a large Roman Candle)... then adjusting the master fuel valve and assuming air pressure in a tank left over from the previous shut down, the fuel/air mixture is adjusted to produce a very fine mist which comes out in the firebox , hopefully hitting the flaming waste. A very noticeable, but muted explosion is produced as the waste ignite the fuel/air mixture. Now one simply waits... depending on the size of the engine and firebox, several hundred or even thousands of gallons of water must come to a boil.
The fireman (assuming you're the engineer) will have finished his rounds of the engine lubricating all the required points with a huge oil can.
Contd