Here are my detailed instructions on how to add an email signature in outlook. This procedure applies for new versions of Outlook including Office365.To create your signature, do the following:
- Open your outlook and click on File ->Options
- In the Options menu go to the Mail tab and click on Signatures…
- In the signature menu select New and type a name for it
- Type your signature and choose if you want it to appear on New Messages, Replies/Forwards or both
- Click OK and your signature will be saved.
There is an option to add more than one signature. You could also attach images and include web links.
The official Microsoft guide is referenced here. It will also include a video guide