At conventions and on Twitter we get a ton of questions about how the trade paperbacks (individual volumes) relate to the hardcovers, how the hardcovers relate to the compendiums, and how to switch between them. The short version is that The Walking Dead is generally broken into 6-issue arcs. Every trade paperback volume collects 6 issues. Every hardcover “book” is 2 trade paperbacks, or 12 issues. And then there are the compendiums, which are each comprised of 48 issues (8 trade paperback volumes). Oh, and if you want to get fancy, we sell Deluxe Hardcover Onmibuses, which collect 24 issues (or 4 paperback volumes, or 2 hardcover books). The Omnibuses are over-sized editions which also include cover artwork and come inside a slipcase.

Individual issues of The Walking Dead come out each month.
The release cycle for paperback volumes is generally every May and November. Certain marketing factors can fudge the release a bit.
The hardcover books generally come out once a year, late fall.

Here’s a super helpful map of the different versions:

book-map

Our “Story” page in the comics section has an issue break down as well as plot details (so don’t expand unless you want to know.