How to Make a Follow Button Link on Tumblrby Tricia Goss
Perhaps there is something to be said for the therapeutic process of blogging, but you probably maintain a Tumblr account because you want to share what you post with others. One way to make it easier for Tumblr users to follow your blog is to add a Follow button. Tumblr provides a half-dozen pre-made buttons that you can add to your blog, allowing anyone who wants to follow you to do so with a quick click.
Log in to your Tumblr account and go to the Tumblr Buttons page (see Resources).
Select the Follow button you want to add to your blog. Click the "Choose Tumblelog" drop-down list and select the blog to which you want to add the button.
Click the "Get Tag" button. Select the code provided and press "Ctrl-C" to copy it.
Go to the main page of your Tumblr blog and click the "Customize" button on the menu bar. Click the "Edit HTML" link next to the theme name in the navigation pane.
Click inside the HTML box directly before "</head>" and press "Ctrl-V" to paste the code for your button.
Click "Update Preview" to see how the button looks on the page. Click "Save" to add the button.