'94 Astra 1.4 - Not starting?

Hi,

My 94 Astra 1.4 has just decided not to start. Have checked

Battery - Fine and recharged just to be sure, but it never sounded like a battery problem, just not firing.
Plugs - Seemed fine colour wise, but replaced just to be sure.
Petrol - check
Connections - All wiring seems to be connected up fine, as per Haynes

It's turning over but just not firing. Anyone have any ideas, I'm gonna check the fuel pump as per Haynes, but one thing has left me a bit stumped, how do you manually turn over the engine?

Any ideas much appreciated.