Engine Removal

This procedure is pretty straight forward.
Take photos as you go: There is nothing more valuable than a digital camera (I mostly used my mobile's camera) when doing this, unless you have a photographic memory.

Transmission: You don't have to remove your transmission (I have an auto) but you do have to either suspend it with strong wire or rope to the car (the wiper motor is pretty strong)  or put a jack underneath it, or both, and also push the torque converter away from the engine and keep it there: If you don't do these things, the front of your trans will drop onto the floor, possibly damaging the mounts and the torque converter will separate from it, releasing about four litres of transmission fluid, also on the floor. This warning is more to avoid the mess than the expense and inconvenience.

Distributor: You will need to remove this, as it can very easily be damaged when the engine is moved. Mark the plug leads before removing the cap, as leads sometimes fall out. A pencil or ball point pen will do, unless you have black leads (if you do, use liquid paper) . I also put the engine on TDC with #1 in firing position then took a photo with the dizzy cap off. My photo of this was a bit rubbish, so I won't bother posting it.
Air conditioner: Does not have to be disconnected. Just un-mount the compressor and hang it to the side, out of the way.
Alternator: Take a shot of this before removal. If you connect anything incorrectly on your alternator, it will be disastrous.