I'll start this post with an obvious fact: Maya is a b*tch. It constantly crashes for unknown reasons and we have start our work from either the beginning or a thousand year old save file.
Simple solution if you have enough space on your hard drive. Either use Drop Box to save your projects there or use the incrimented save function in Maya.
First step click on the additional options box beside the save as... button.
There you will find the incremented file check box.
From now on,every time you press ctrl+s with your fat filthy fingers,your file automatically saves a new file instead of re-writing the old one. You will find your save file history in the Incremented Save folder beside your scene project file.
The end. I want to die.
"Think you got what it takes to be "creative"? Then welcome to the other side of sanity."