The official docs-page from Microsoft provides information to the major releases, i.e. V. 8.6, 8.7, 8.8 and so on:

https://docs.microsoft.com/en-us/dynamics365/customer-engagement/field-service/version-history

Also the latest generally available Woodford Mobile Project Template versions incl. download links and the Woodford solution itself can be found on the site above.

However the minor update documentation is not directly linked from the above mentioned page. Therefore I (try to) list all the update announcements I come across here:

Minor Update Versions

V.8.8.3.533 (Sept. 10, 2019)
https://cloudblogs.microsoft.com/dynamics365/it/2019/09/10/enhancements-and-bug-fixes-for-field-service-version-8-8-3-533/

V.8.8.2.160 (August 11, 2019):
https://cloudblogs.microsoft.com/dynamics365/it/2019/08/11/enhancements-and-bug-fixes-for-field-service-version-8-8-2-160/

V.8.8.1.45 (July 07, 2019):
https://cloudblogs.microsoft.com/dynamics365/it/2019/07/07/enhancements-and-bug-fixes-for-field-service-version-8-8-1-45/

Field Service Mobile Updates

Mobile App V.11.3 and Project Template 1.0.2735 (September 30, 2019)
https://cloudblogs.microsoft.com/dynamics365/it/2019/09/30/release-notes-for-field-service-mobile-app-version-11-3-and-mobile-project-template-version-1-0-2735/

Universal Resource Scheduling (URS) Updates

V.3.8.0.105 (June 11, 2019)
https://cloudblogs.microsoft.com/dynamics365/it/2019/06/11/enhancements-and-bug-fixes-in-universal-resource-scheduling-urs-version-3-8-0-105/

Resource Scheduling Optimization (RSO) Updates

V.3.0.19263.1 (October 3, 2019)
https://cloudblogs.microsoft.com/dynamics365/it/2019/10/03/whats-new-in-dynamics-365-resource-scheduling-optimization-version-3-0-19263-1/