If you want to embed a Twitter Follow Button in your website you can use their Generator. It has limited configuration options.
To style it your way you just need to know that a follow me is triggered by calling the link
<a href="https://twitter.com/intent/follow?screen_name=leifhanack">Follow me</a>
where screen_name is the twitter account name. Either with or without leading @.
Photo by Todd Van Hoosear