UPDATE: YouTube has changed the button page, so now, if you want a subscribe button you will have to create your own image, and link it to your subscribe link.
Create Your Own Images:
https://my.wealthyaffiliate.com/training/create-a-custom-logo-or-banner-with-gimp
Put Images In Your Sidebar
https://my.wealthyaffiliate.com/training/adding-an-image-to-the-sidebar-of-your-wordpress-blog
YouTube Subscription Links (put your own username)
http://www.youtube.com/subscription_center?add_user=USERNAME
http://www.youtube.com/subscribe_widget?p=USERNAME
Both of these link work, but will take you to 2 styles of subscription pages. The choice is yours which one you use.
Did you know you can add a special button that allows people to go from your website directly to your YouTube channel? YouTube already has the hook-up with cool buttons, ready to copy/paste somewhere on your site. I take you though this process in this video.
Here's the (old) location of the YouTube buttons
www.youtube.com/t/creators_downloads
Let me know what you think in the comment box below, and don't forget to 'like' it if you found it useful.
It's probably staring me in the face, but I can't find it. Cheers, Caden