This module allows you to put an internal link to existing content. So you can combine your nodes the easy way. Also files, taxonmy terms,... can be used.
After installation you need to make a profile first.
The matcher gives you the possibility to choose your goal.
The atrribute function allows you to open the link in another window e.g.
Now you have to set active the linkit button (last one in the row) in an text format (here full html)
And choose your profile...
How does it work? You select a word in your text. Click on the linkit button en while typing, the according content will appear.
The module links the according content with the node. Mind the option for opening in another window.
Linkit has also a image view mode. The picture can be seen as a thumbnail with a link towards the file.