Good news: There really isn't much that you need to learn about the app. When your department chair has signed your Summary Form, you should receive an email notification. At that point, you can go in and:
Your new Summary form for this year should show up here. Click on the link next to it and you will have the following options:
First, read through the form, especially the comments
Then, click on the box to say you acknowledge receipt of the form. (Note: This does not indicate that you agree with the form, but that you have read it.)
If you would like to discuss your evaluation with your Department Chair, there is a box you can check to request that; that means your evaluation does not move forward to the Dean until this meeting has occurred.
There is also a box where you can add any comments to your evaluation (this will appear on the final Summary form).
Sign and click on the "Submit" button. It is important to sign and submit; if you do not sign, your form will automatically move forward to the Dean for their signature without your acknowledgement (at which point, you will have missed your chance to have any input into the process). You should receive at least one (usually several) reminder emails before this happens (you should always have 2 weeks or more to sign).
You can also review/print out your signed/archived Summary from from previous years. (These are also stored in your Human Resources personnel folder.)