DnnDeveloper's Contact Us module is a simple module to implement a contact us page along with google map. It can easily integrate into the DotNetNuke portal and can be configured to match the layout/Skin.
Contact Form Builder module is the easiest way to design and generate the dynamic form, you can select/drop as many fields along with the options for the controls as per your requirements and end users can post the details to submit the details to the configured email address.