The sidebars are the blue text columns on the left and right side of the screen. You can edit them by following the links in the translator's menu.
If you click on 'Edit the left sidebar', the sidebar will be shown in the middle of the page.
It will now have editable sections (see the images below).
To edit a section, you have to click on one of the 'edit' links.
The top part of the menu is not editable but the sections under it are.
If you click on an 'edit' link, you will be taken to the text editor, where you can edit the chosen section. It works the exact same way as the editable sections in the main text.
When you edit the sidebar, the internal links suddenly get red arrows. This is because the sidebar is now displayed in a part of the page (the middle) where red arrows are automatically appended to internal links. Once you finished editing the sidebar, the red arrows will disappear.
The sidebars contain a lot of code. Ignore the code and look at the plain text.
For example, if you edit the second block displayed in the image to your right, you will see the following code:
<li>[[Main.AboutThisSite| About this site]]</li>\
<li>[[Main.AboutMe | About me]]</li>
<li>[[Main.Contact | Contact]]</li>
<li>[[Main.HowYouCanHelp| How you can help]]</li>\
The only text you need to edit are the words typed in red. You can ignore all the rest.
If you have difficulties editing the sidebars, just let me know and I will edit them myself after you finished translating the pages (where I will find the page titles).