A short manual for a castle owner: how to set up the sale of seeds and the purchase of crops at the chamberlain, which prices and rewards to choose so that players bring crops to your castle, and what to do with the crops afterwards.
Here is a simple little manual showing that even a plain cook can cope with the settings in a castle in 10 minutes, without understanding the manor at all. How to sow and hand in crops is told in the article All about manor: sowing, harvesting and handing in crops.
First of all we go up to the castle chamberlain (he stands next to the throne), choose the item "Manage castle vault" in his menu and throw some 150-200 million adena into the castle treasury.
Then we choose the item "Manage manor", and after it the item "Edit seed setup". Here we will set up the sale of seeds. What price to put on the seeds? Put the maximum: whoever needs seeds will buy them at any price.
Now how to find out these maximums? It is simple: click on any line with a seed, and a small window with a menu will appear. In this window we must enter the number of seeds sold tomorrow and their sale price. The maximum number of seeds is written right there in the window; to check, you can enter a deliberately wrong number in the quantity field (for example a very big one, 1111111111). One more window will pop up reminding you that the number of seeds can be from and to, in our case from 0 to 810. We enter 810 as the quantity. In the same way we find out the range of sale prices and get from 30 to 500 adena per seed. We put 500, of course. That is how we set up all the seeds. Putting alternative seeds on sale makes sense only for scarce positions, since nobody will buy small seeds in the alternative version for sure.
Having set up all the lines in the seed sale this way, we press the "Yes" or "OK" button. That is it, the sale of seeds is set up.
The purchase of crops is set up in a similar way: we go to the menu item "Edit crop setup" and set up the purchase of each crop in the same manner, only here we also state which reward will be given for handing it in, "Reward" 1 or 2. After setting up the purchase of each crop, look at the lower left corner of the table: the window there shows the sum that must lie in the castle treasury for the buying and selling to start working tomorrow. If everything is fine, we press "Yes" or "OK". Now we have set up everything that is needed.
Which prices and rewards to set
Some thoughts on the purchase price of crops. To be honest, I always set the maximum prices. After all, the higher the price, the more resources a player gets for the crops handed in, and the more often they will manor and hand in crops precisely to my castle. From time to time I even hear talk at the manor manager when crops are handed in: "Who has Gludio? Vizavi? OK, I'll manor for her first, she always has the maximum set".
And I can still understand the top castles: there the simpletons will hand in crops at any price; they do not even know that for 1,000 
Desert Codran you can get not 50 
Durable Metal Plate, as they do, but 1,000. That is their problem.
But when the owners of backwater castles set minimum purchase prices there, that I cannot understand. They sit for two weeks and wonder why nobody hands in crops to them. Well, go on sitting. Sorry that the resources will go to somebody else? Drive your clan members out into the field, let them go and manor and hand in crops.
And one more thing about the first or the second reward. Use your head when you choose the reward. An example: the crops of 
Blue Coba, the first reward is the red mold, the second is 
Crafted Leather. In the castle they stubbornly set the first reward every day, the red mold, which is needed in minimal quantities and which nobody takes any more, since everyone's warehouses are stuffed with it, while the so much needed Crafted Leather never comes from the castle owner. Or the small crops of 
Dark Coda: why set the first reward 
Stem, if everybody will re-craft it into 
Braided Hemp anyway, which is exactly the second reward for this crop? And there are very many such examples.
Get yourself a character, give it one crop of each kind and during the day check several times at the manor manager what is happening with the handing in of crops to your castle, and after that in the evening make corrections to the reward or the price, so that all the crops in your castle are bought out every day.
What to do with the crops handed in
Those to whom crops were handed in after all wait a day and then check the clan warehouse. Ripened crops have already appeared there: these are the same crops that were handed in to you, only the word Mature is added to their names. There are fewer of these ripened crops than were handed in; some say 10% fewer, some say a third. I do not know, I never checked. With these crops we go to the castle basement, to the castle crafter, and craft what we need.
And to ordinary players who have read this guide I advise not to rush headlong to hand in crops at any price, but to think about how much the owners of the top castles will craft for themselves, having bought up your crops for a song. And the more top the crop, the fewer of them are needed to craft one thing. When I own Goddard, up to 80kk adena a day goes on buying crops at the very maximum prices, but for that I get several warehouses completely stuffed with skill enchant books and A armor scrolls, not counting stacks of craft stamps, quick step potions and so on.