Frequency and format in Facebook publications

[musicanueva]

Hi there,
first of all good morning and thanks in advance for your help.

To promote the posts of my webs I usually use HootSuite to program publications in Facebook...
BUT: there are guidelines to improve the results?

I actually publish just 1 post on the official FB wall, just text (no pics, neither videos)

Any help?
thank you
Sandro