If you want to add an image, such as a company logo, to all or just certain reports, the easiest way to do that is with a template. Using the Template Editor, you can add a picture object to a template that uses the desired image. Any report using that template then displays that image.
However, there's a little easier way to do this. One of the stock templates, Professional - Blue with Logo, already has a picture object on it. This picture uses whatever image you upload using the Upload a Logo Image function in the Tools menu. So, simply upload a company logo and use that template for your reports. Note that the Upload a Logo Image function is only available for Administrator users.
If you want a different template to work the same way, do the following:
Use the Template Editor to create or edit the desired template
Add a parameter to the template named LogoImage
Add a picture object and set the Data Binding Image property to the LogoImage parameter