It is possible, using GriefDefender, to claim an area of land to protect it from griefing.
There is a tax involved which is $0.125 per block ($32 per chunk).
Note: Claiming is optional. Griefing is forbidden and claiming land is for your peace of mind.
Creating a basic claim
You can create a basic claim easily by using a Golden Shovel in basic claim mode (/basicclaims). Click on one corner, and then click on the opposite corner as indicated by the diamond blocks in the image provided. If you have enough claim blocks, your claim will be created.
Resizing a claim
You can resize your claim by using a Golden Shovel. Resizing a claim is the act of moving a claim corner. Click on the corner you want to move, and then click on the block you want to move it to as indicated by the diamond blocks in the image provided. If you have enough claim blocks, your claim wil be resized.
You can trust other players in your claim by using the /trust command while in your claim.
The syntax for the command is /trust <player> [<accessor|builder|container|manager>].
This is what each of the trust types mean:
Accessor - Use of doors and switches
Builder - Break, place and interact with everything
Container - Use of containers
Manager - Builder + managing the claim
Abandoning a claim
To abandon a claim, first be inside the claim and then use the command /abandonclaim, confirm the abandoning and the claim will be removed. Furthermore, to abandon ALL your claims, you can use the command /abandonallclaims.
Creating a subdivision claim
Creating a subdivision claim is similar to a basic claim with the exception that you need to be in subdivision claim mode (/subdivideclaims). From there, you'd click your desired corners within your basic claim. This does not require additional claim blocks and allows you to set flags independent to that of the parent claim.
Changing claim flags
You can change a variety of flags for your claim by using the command /cf while in your claim.
In the UI, you can toggle specific options to true or false by clicking.
There's two different types of flags: public and owner. The latter affects the claim owner and trustees, while the former affects everyone else.
/cfr will reset your claim flags.