The milestone report document is part of the project schedule plan, and it should be constantly updated (for example, when a milestone is finished, when a milestone is delayed, etc...) A milestone report is (usually) an Excel sheet that consists of the following columns:
1. Milestone name: The name of the milestone, for example, "painting the building"?
2. Description: The description of the milestone, this is usually a brief listing of all the high level deliverables falling under this milestone (a milestone can consist of several deliverables).
3. Start Date: When will we start working towards this milestone.
4. Actual Start Date: When did the work towards this mielstone effectively start?
4. End Date: When will this milestone end?
5. Actual End Date: When did this milestone actually end?
6. Status: What is the status of the milestone (not started/on hold/ongoing/cancelled/done)
7. Other information: Other information (or comments) that can be added about this milestone.
The milestone report will also include number the following information:
- Total milestones
- Total ongoing milestones
- Total due milestones
- Total done milestones
Note that if you divide the done milestones/due milestones and you get a number that is lower than 1, then your project is falling behind and is not meeting all of its milestones.
I think that my answer is better than just linking to a project milestone template! You're able now to create this report yourself and it won't take you even an hour because all the information comes from the project plan.
PS: The milestone report should be sent to the project stakeholders on a regular basis, preferably embedded in the project status report