How can I add help tips on each page, like a sliding panel? Is there any module I can use to insert in every page info about the specific page. I could use something like a sliding panel, or a popup. I need the content of that, block or popup or whatever it is, to be translatable.
I found this link, but it needs much custom code, which I would like to avoid.
It sounds as if https://drupal.org/project/popup may be suitable for for your needs.

You could create a block with various contexts (your translations / page) and then use this module to display the block (using sub module 'Popup Block') on each page when the user requests it, by rollover or click or whatever you choose.

The module is mature, widely used, has a recent version and has documentation provided.