I could help you out with this but will require a little more information about what you are trying to achieve. You can contact me at your nearest convenience at grant.mills@mailgloo.com
Your question is a wee bit vague. Are you asking :
How to technically include a link? or
How to start to visually design your template (if it's graphics based)? or
How to write the content that it gets a decent number of click-throughs to your site?
Are you at the very start of wanting to define your email marketing strategy?
Cheers.