Hotmail provides user with option for adding personal email signature. This can be done using the Hotmail Options
Click the Options link available on the right hand side of your hotmail inbox and select More options from the menu list.
Navigate to Customize Your mail section and click the Personal e-mail signature link. This would display a rich text editor using which you can customize your email signature.
After adding the required details in the text box, click the save button to confirm the changes. Now this information would be get added to bottom of all the email messages sent from your account.