The Wordpress part is the easy bit. That's basically taking your static HTML pages then converting them to PHP and inserting the Wordpress tags to pull content from the database. In some places these tags will be in a loop, e.g. for a list of pages.
The most difficult part is the design. You should identify the page types you want (e.g. main page, lists of posts, static pages, about) and create the actual templates with mockup text. ONly when you're happy should you think about the Wordpress part.
If you search with Google you'll find plenty of pages on creating your own Wordpress theme or converting HTML to a theme.