You can use tags or notebooks to divide up what content you want to review. Once it's reviewed, ask yourself "will I ever need to reference this?" - if the answer is "no" delete it. I usually only save often referenced material or material that is hard to find if I lose the source.
To expand on this. Say I have a few projects - writing a book, fishkeeping and personal finance. When I clip or find an article that I don't have time to read, it goes into the inbox. When I process my inbox, each article goes through the GTD workflow. Do I need to read this? Can I read it now? Do I need to read it later? From there it is deletion, a next action or read.
The great thing about evernote is the tags. Say you decide to read it now or later. Tag it with
next for reading. Title the note read this fishkeeping article. Put it in your
next actions folder.
Say you are clearing your to do list and you run across review this personal finance table note. You take a look at it and read it. You come across some useful information - maybe you want to jot it down into your
personal finance notes and delete the article, no problem. What about the review this academic paper for book note? Well, you read it, it's full of information that you need to reference as source in your book. This, you say, I'm keeping! So you adjust the tags - remove
book. Now you title the note Reference from Cambridge University paper on Astrophysics take it out of
next actions and toss it into the
File Cabinet notebook you have.
You went through three articles, pulled information out of one, saved one completely, and read and tossed out another - all based on what you want out of the information from the articles.
The key is how you manage the notes with the articles. Tag them appropriately. Most importantly, for me, is to title them with action verbs. Right? Every note that needs to be processed is titled read this or review this. Once I've done the action, its title is changed to the next action or it is given a final title explaining the content of the article and is filed away.