It is good practice to save your work often when you are using any kind of software. You don't want your work to get lost when something goes wrong.
When I work with SPSS datasets, I make a copy first (I make mistakes and I want to make sure I have the original data).
Open the dataset and before you start anything else go to File, choose Save As. Save the dataset with a new name. I like to include the date I work on it (don't forget that you cannot use a dash, slash or space).
Once you have done this you can just hit the save button as often as you remember (remember to do that very often :))
Please save your output as well!
If you want to share your output with somebody who doesn't have SPSS you can export the output as a Word document.
Don't forget to set the page as landscape and to shrink tables to the width. It is sometimes tricky to remember where you are saving your document - click on the box