What is a wireframe you ask?
A wireframe is used in helping to plan out what will go where on your website and how many pages the website will have. This is a good way to plan out your website navigation and how all the pages are connected. It can also help you plan out where you want different areas of content to go. Usually this is done in the early stages of planning out a website.
Think of a wireframe as a diagram for how a website will work and function.
Below is an example of a wireframe image for the homepage of a website. You would also need a similar image or diagram for each page of this website. Other larger websites may have many pages that follow the same format, so the same format could be used over again.
Wireframes can be hand drawn but it is usually easier to create them using software like Visio or even Photoshop. You could also try online editors like wireframe.cc. Using software has the advantage of being easily updatable if your client needs changes to the design made. It is also easier to save the design and email to your client rather than having to scan a physical drawing.