It is quite possible that you will not find something so specific as an SEO organisation, whereas you might find material suitable for a manufacturing company for example.
However, the point here is that every organisation is different. You need to write manuals SPECIFIC to your company and it's policies and procedures - which will be different to other companies policies and procedures.
So, on that basis, you can use manuals that other members have posted here as a guide to content, format and layout, and ADAPT them to suit your requirements.
If you want someone else to do your work for you, I would suggest employing a HR specialist to come in and write your manuals.
In the time you have taken to post a query, wait for answers, and now debate the issue with me, you could have found some sample manuals on CiteHR, and be well on the way to having the first draft of your own manual written.
All I want to do is to encourage you to use the fantastic resources you have at your disposal here on CiteHR and adapt where necessary to meet your organisational requirements.