Are you looking to upload the PDF files that are manuals?
If so you can upload them to imagetex.com and link to them back here.
 
upload the file to imagetex.com, once done, put it in an album and then click on it after youre done, you should get a screen like this:
 

 
 
Right underneath your PDF file you will see the text that says:
 

 
Simply past that text (without the IMG before and /IMG afterwards around it) in to your post and the file should link right up.
 
http://www.imagetex.com/albums/userpics/10022/000275.pdf