You can either download the files to your hard drive or view them online. Also, you can submit your own files or e-books to share on the website for others to take advantage of them. Of course that you will be subject to restrictions of copyright if you upload unauthorized material.
The site organizes its content in two major sections, one which has featured documents and another one with the latest additions to the site.
The range of topics is really wide, you can find from instructions on how to store fruits and vegetables for commercial purposes, guides for high school courses, or user manuals of routers and other electronic devices.
Aspdf.com gathers this material from submissions and links to them in the servers in which they already are, but do not host the files in their own server. They call themselves “a compilation of public information available on the internet”, and publish the files “as is”, without assuming the responsibility of the contents you’ll find in the documents or any change that may eventually happen to them.
None of the above though, is an obstacle for finding interesting texts that will help you out in many possible situations. Aspdf.com is an interesting resource to have in mind.