I notice that in every book I have always start a new chapter in an odd page and it leads me to wonder why.
I have some written work that's about 40 pages long and 7 chapters; should I follow that rule?
If I do, the reader will definitely see blank pages before the start of a new chapter occasionally.
Why do new chapters in books usually start on an odd page?
It's recommended to start new chapters on the recto page of a manuscript, as it establishes a predictable flow for the reader to follow. The resulting occasional blank pages are actually a part of establishing this rhythm, making the divisions between chapters even more distinct. This recommendation is listed in rule 1.48 requires login of the Chicago Manual of Style.
The recto page is considered the front of each leaf, and is the right-hand page when dealing left-to-right languages.