Not being too strict with this.. basically just a few things you need to keep in mind, such as:
1.)Accuracy. There's something wrong if you're talking about mage logs in an arma solo guide
2.)Clarity and organization, it helps if it makes sense lol
3.)And most of all keep it updated. If prices change or a new item or items come out make sure you update your guide to include those if they make things better
Thats about it, good luck