Because Plesk is not a product of 1&1, only some of the most common questions are covered in the FAQ. There is a help link within Plesk at the lower left-hand corner that opens the Plesk Administrator's Guide in a new browser window.
You can also visit the Parallels Plesk FAQ site for more information.
For other, more severe issues with Plesk that do not fall under general administration, it is best to contact our Dedicated Server Support team for further assistance. If necessary, an agent will create a support ticket with Parallels for more insight into Plesk functionality issues.