[support] Altering HTML in views block displayed in panel

I'm using a view block as a panel page on my front page, and the view is a list of blog posts displaying the title, date/time posted, and who posted it. I need to do two things: 1) Add divs around the block so I can add my rounded corner graphics 2) Add some text in front of the name of the poster What override function do I use to modify the markup for this block? Would it be theme_block()? Or another one? Thanks. Steve