The reviews you write now will serve as references in the future for junior colleagues reading the same materials. By all means, post your reviews. You can post a review by selecting "Write Review" from the bibliography details screen.
However, note that the library checks each review before it appears on the screen in order to determine its appropriateness. Therefore, it may take some time for your review to appear on the screen. The library may keep a review from appearing on the screen. Your understanding is appreciated in such cases.
Note that your personal information is kept confidential. Information on the people posting reviews appears as nicknames and the like.