QUESTION Problem With Adding Hooks

[Dale]

Okay, so I'm new to the rear-end of Get-Simple. I've decided to get started on making plugins. My first plugin requires me to insert HTML dynamically right after the body tag of every page. How would I even go about making a custom hook to do this? Or is there one available out-of-the-box that I am missing?

EDIT: Got that working, now another problem... how do I dynamically push my hook into the header.php after the body tag?