Obviously, in all cases, the responsibility for maintaining current documentation (and acting upon changes) remains with you. I would try to have the periodic check solely as a back-up, make it a documented requirement with the originating organisation that they must keep you up to date.
For (engineering / quality) standards, all the major sellers have a free update service.
For regulatory updates, these are usually free and online, albeit not necessarily easy to find, and not always easy to interpret the impact of the changes. For EU stuff I would recommend discussing with your Authorised Representative. If you have a regulatory person, get them on the task, it is their job. (N.B. they don't have to know it all, they need to know who to talk to).
Also, don't underestimate the value of the Cove. It's not perfect, but it is very, very good for this kind of thing.
For suppliers, your agreement with them should include a clause about updating you (i.e. on documentation both sides agree you need).
In the US especially, an easy auditor target are the Materials Safety Data Sheet binders that many factories have to have, and display prominently.
I imagine it is illegal, and certainly a liability, to have out-of-date MSDSs on the factory floor.
these documents are not written by the company, so by definition they are of external origin.
Are you really only going to check once a year? What would that check actually involve?
In reality, I often find there is no proper system, but that the binders are indeed usually up-to-date. It's "advanced luck" if you like.
So find out what the system really is for ensuring currency, review of changes, distribution and determing any required training? Then document that.
In terms of creating a procedure, check where this external doc control system needs to be different from your regular doc control system? (I.e. minimise the need for additional systems).
Edit: You then use to periodic reviews to ensure nothing critical has been missed.