When you are invited as Associate Editor for a manuscript you will be notified by a Email and also text massage on your cell phone.
When you login to the website with your user name and password, click on “Associate Editor Area” that is marked by a red number. This red number indicates that you have a task in this area.

In “Associate Editor Area” click on new invitation. The number in front of each item shows the number of manuscript that you are invite to review as associate editor.

In “Pending Assignments” you can find the manuscripts that you are accepted to review but did not complete the review yet.

“View AEs Activity” you can find the reviews that you completed them.

You can click on “View All Reviewers and Activity” to find the reviewers that are good in review (like answer on time).