larger version here) I'm using for Last of the Polar Bears. You're welcome to download and print it out for use in your own comics.
The template is sized for printing on standard letter-sized paper. There's a space for you to draw your comic page, a place to keep track of the page number, and a place to indicate starting date. I find marking the date useful for keeping track of my daily page output. The empty space has a purpose as well. This is where you can break down panels, write notes, and try out different ideas for panels configurations, poses, and expressions before you commit to them in the actual layout. See my previous post for examples.
I originally created this layout for use on Peach Fuzz, so the trim and bleed sizes are suited for a standard 5"x7.5" "manga"-sized graphic novel. The black bars on the top and bottom are there as space fillers because the dimensions are intended for penciling on a traditional 11"x17" comic page.
Book sizes vary, as do individual publisher's designated trim and bleeds. For example, I use a different page template for penciling comic pages for Archie Comics. Think about your desired final output size and plan your rough layouts accordingly.