Books written by the Maya were made from tree bark that has been flattened, covered with a lime paste & folded accordion-style and were usually written on both sides.

...

l..

When the Spanish conquered Mexico in the 1500's, they burned all of the Maya books they could find. They surviving books are called codices (codex is singular). There are only 4 "codices", the first 3 which are known by the name of the city in which they are now located; Dresden, Madrid and Paris.The fourth codex is called the Grolier and was authenticated in 1983

The contents of the codices must have varied, but some of them were evidently similar to astronomic almanacs. We have examples of a Venus table, eclipse tables in a codex in Dresden. There is a codex in Paris that seems to contain some kind of Maya Zodiac, but if it is and how it must have worked are still unknown. Another major example of Maya almanacs are present in the Madrid Codex.

...

...

These codices probably contained much of the information used by astronomer priests or the noble class to determine dates of importance or seasonal interest. The codices probably kept track of dynastic information as well.