I have been an admin of a page for quite a while now. I wanted to document some points that one have to take in mind while posting on pages. Cause with greater power comes greater responsibility.

1. Don’t Spam:

A page should have interval between posts. No one likes an endless stream of posts consecutively over a short period of time. You can use apps such as Hootsuite to schedule posts over optimal intervals of time for a greater impact.

2. Try to engage readers:

Ask for feedback, like, ‘do you think…’, ‘will you…’ etc in the end of your posts.
Don’t post a link directly as a post. Always give a preview of what the link is about.
Instead of “Checkout this link for new Samsung S4″, you can post something like this, “Samsung S4 seems a really cool gadget that have taken us for a ride ever since we have got our hands on it. It has this and that feature. You can checkout this link for a hands on review…”.
Point is to make a user “engage” and get their attention and if you get successful in doing that, your reader will automatically want to read more.
Remember, readers don’t like posts to which they can’t connect to. While on the other hand they don’t like posts which sounds too artificial too. So, try not to overdo it!

3. Your posts on a page is not personal:

Remember on a page, you are not posting personally, but you are representing a page. People don’t know the admin behind a page, but they do know the “personality” of the one behind it. So, instead of “I think” you should post in a passive voice. Like, “We think”, or “(page name) think”, or “admin of (page name) thinks” sounds more professional.

4. Don’t use flaming language:

As an extension to the above point, it’s not a good idea to flame user.
Since you are representing an “entity”, you can’t really take sides. You can’t flame a reader, even if they are incorrect. Its like, instead of telling “they are wrong”
tell them what is right. That means, no pointing fingers personally.
Say, someone posted, “windows rocks, Linux sucks”, you can reply, “well, Linux have many useful features which Windows is far away from. Try this, this and that… we are sure you will like it.”
Point is not to reach to conclusion, and let user decide whats best.

5. Less tl;dr posts, more images:

Try to post images more than long text based posts, that readers might find it too long to invest their time in. A sweet image with a catchy caption have higher rate of shares and more potential of becoming a viral material.

6. Its OK to share stuff from other sources if credit is given:

Facebook, or Internet in its entirety have one thing at its core: “Sharing”. So sharing someone else’s content is acceptable as long as credit is given where it’s due.
Of course, this all comes down to personal ethics (next point) and whether your page is commercial or not (in which case sharing other’s content would be plagiarism). So, discretion is advised.
Of course, original content has its own unique value.

7. Ethics

There are some ethics that every page should have. For eg, Don’t like your own posts as a page owner. You may like comments though, as long as it’s genuinely good, since that may be a subject of jealously among other fans who comment.
Also, as an extension to the 2nd point, to engage users you should also reply to queries that fans have asked. It’s not a good ethic to leave your fans starved for a query, specially if it related to the post you made. This is good as long as comments don’t run out in hundreds (or thousands), in which case it’s not even remotely possible to answer all of the queries.

8. Treat your fans with dignity:

Nothing is more precious than someone giving you time. But it’s possible that sometimes fans don’t respond well to your posts, like you expected. Even when that happens you have to understand that likes and/or comments are not the only important factors.
Remember, if the page is not commercial, it pays to see those likes and comments. And it gives a warm feeling to see you made someone aware of cool stuff!
That’s enough for some.
And lastly the most important point is,

9. Don’t forget to Enjoy

After all if your page is not (yet for) commercial, the only reason you are posting is because you enjoy doing so! 🙂