When you open a page template you should always go to File>Bleed and Margins and make sure both of these toggles are on like this image shows. That will help you stay in the "Safe Zone."
The gutter guides are drawn in Express for you too and should be hidden when you are ready to turn in the final file.
BLEED (The "Run-Off" Area)
Definition: Extra background image that extends beyond the edge of the page.
Why we need it: The printer cuts the paper with a giant guillotine blade. It isn't perfect. If your photo stops exactly at the edge, you might get an ugly white sliver when they cut it.
The Rule: "If a photo touches the edge, it must go PAST the edge."
TRIM LINE (The Cut)
Definition: The actual physical edge of the page where the scissors cut.
Visual: In Adobe Express, this is the edge of your white canvas.
LIVE AREA / SAFE ZONE
Definition: The safe area inside the margins where important stuff (text, faces) lives.
The Rule: "Keep faces and names inside the Safe Zone. If they go outside, they might get chopped off."
SPREAD
Definition: Two pages that face each other (e.g., Page 2 and 3). We always design in spreads, not single pages, because that is how the reader sees the book.
GUTTER (The "No-Face" Zone)
Definition: The 1-inch strip right in the middle where the book folds and is glued together.
The Danger: If you put text here, it disappears into the crack. If you put a face here, they look like a cyclops.
The Rule: "Respect the Gutter. Keep it clear."