When you want to add your company logo by default in all new word documents then you can follow the below mentioned steps. In this example we are using Word 2010 for creating the template, you can follow the same steps when using Word 2016 and Word 2013 as well.
Step 1:- Click File menu then New and select Blank document.
Step 2:- In the new document, Add new header to the document using the Insert menu.
Step 3:- Copy and paste the company logo in the document header.
Step 4:- Then to save the template, click the File menu and select Save as.
In the Save as dialog box, set the Save as type to Word Template and enter the File name for the document template. Make sure the save the template under Microsoft Templates location.
Step 5:- Now you can use this template by clicking the File menu –> My templates and pick the saved template from the list.
Click the OK button after selecting the template with Create New radio option set to Document.
Step 6:- Now the new document by default will have the company logo as part of the header section.
Similarly you can add other default fields such as Title, Date or any predefined text.