How to Mail Merge in Word 2010
Firstly Navigate to Mailings Tab
Now Click Step by Step Mail Merge Wizard.

Carefully Choose the type of document you want.
This step will ask you to choose what document to use/type document now.

Now Choose your recipients


Click Open.
Follow the rest of the Mail-Merge Wizard.
It depends on the options chosen different dialog boxes
will show up, making very difficult to provide a step by step for the
rest. However; the rest of the steps are self-explanatory.
Lastly Click Finish and Merge on the Mailings Tab when done.