Based on the Step-by-step: Speed Up WordPress with Varnish Software article originally written by Federico G. Schwindt and published on Web Designer Magazine - http://www.webdesignermag.co.uk/ as well as on the Varnish Software blog.
It is now available in the Varnish Web Developer Wiki, specifically under the Varnish with WordPress Tutorials section. As with any other wiki docs you can help us to expand it and keep it up to date. I'm publishing it here in the blog for reference. Read on: