to work with several persons on one document or book?

If you set the Netwok File Locking preference, then you will get a warning about which user is currently working on the document/book. You can override the lock and edit, but whomever saves last, overwrites the other's edits.

Otherwise, without a content management system, it's more of an honour system and you have to discuss amongst your co-workers how you will work on things somewhat concurrently. It's easy enough to work on separate files in a book, but you mustn't do any book updates in that situation.

Also, keep in mind, that FM doesn't always play nice with network locations and it's recommended to work with files locally - however, this could impact how some content is linked (relative or absolute) and subsequent maintenance.

Only with a source control system to manage the checking in/out of docs & books.