Jörgokayokay i do some screenshots.
first i create a blog/post not a page like here –> http://mreiner.bplaced.net/wp-content/uploads/2014/12/create_a_blog.jpg
and this blog/post contains a image that links to a pdf file like here –> http://mreiner.bplaced.net/wp-content/uploads/2014/12/show_blog_in_right_sidebar.jpg
as you can see this should show up on the right sidebar.. but the point is it should not show up on all sidebars everywhere on the website. no, it should only appear on specific pages in there sidebars. and currently on the old website i can create custom fields in that blog and in this custom fields i put the id´s of the pages .. an tell the blog that he should appear on this, this and this page on the right sidebar and nowhere else. –> http://mreiner.bplaced.net/wp-content/uploads/2014/12/custom_fieldsPostIDs_of_otherPages_in_that_blog.jpg
so all i want is to create posts/articles and tell them that they should show up on the right sidebars on specific pages. important for venues, descriptions, prices etc.
cheers, j.