Go to Peaceful Hall of the Forbidden Palace, Northern Scenery and speak to Lord Wu. Ask to 'buy other things'. You can choose between: Mart Controller, Guild Trainer and Guild Nurse. Click on one selection and buy it (only Guild Leader and Counselor of an AAA rank guild can buy). After that, return to guild house.

Placement

You'll find you have a key item in your inventory named after the hire you just made, you'll need to double click this key item whilst in your guild house to place the NPC.

Double click on Guild Trainer, an NPC will appear in the guild house, that is Guild Trainer. After that, right click on it, you can leave your pets in her care. Those pets are also guardians of the guild house. Any trespasser must defeat those pets to get in. If pet is stunned out in protecting the guild house, it won't be affected at all. Everybody can check his pet, but only guild leader can take them out.

Double click on Guild Nurse to place an NPC. Right click on her to replenish your marching pet's life. But one point costs one silver. All income will be sent to the guild fund. Placing your nurse in an area where many players train may earn you a great income if people regularly come to you to heal instead of traveling to a city.

In the map occupied by your guild (outside the guild house), double click on Mart Controller, then an NPC will appear. With it, pet vendors can be set up in this map. Click on this NPC to change fee and tax rate. All income is transferred to the guild fund.