“Taking Care of Business” is the second Thieves Guild Quest in The Elder Scrolls V: Skyrim
You get “Taking Care of Business” after completing the quest “A Chance Arrangement”.
Find Byrnjolf at the Ragged Flagon
Byrnjolf will give you a test. You must make your way through the Ratway to the Ragged Flagon. There, he will formally introduce you to the organization he represents. Turn toward the South. Head down along the waterway. You find the entrance to the Ratway in the wall.
Once inside, head down the stairs. Start sneaking as you approach the first corner. You can hear Hewnon Black-Skeever and Drahff talking. Take them out and continue to the Northeast through the Ratway. In the next room, turn to the Southeast and head through the doorway there. Go to the South, drop off the ledge and turn to the right.
You will find a door. Look at the bottom right of the door. There is a trap that you can disable there. It is not too difficult, being Apprentice difficulty. Disable it, head through the next room.
Turn to the South after that and continue along the corridor. Open the next door and you will encounter Gian the Fist. This man will immediately rush you and start punching you. Kill him and head through the far door. Follow the corridor forward and then take the stairs up on the right-hand side.
Go through the nearby gate at the top. Go through the room with the axe stuck in the stump to the North. When you reach the next room expect to encounter a Lowlife. This person will immediately attack you as well. Kill him, turn to the East and head through the door to the East. Be sure, before leaving the room, to check the table for a copy of Beggar. You will reach your destination.
Head inside and go to the far end of the room. You will find Byrnjolf waiting for you there.
Collect Keerava's debt
It is suggested that you talk with Talen-Jei at the Bee and Barb. He apparently has good information on Keerava.
Head back up to Riften itself. You should have little trouble finding the tavern. Go inside. Talen-Jei is very easy to find. He is the male Argonian there. He works with and wants to marry Keerava. Talk with him about the debt and he will reveal that she has some family just outside Marrowind. He will say to mention that to get her to buckle.
Go over to Keerava and talk with her. You will see the option to mention the debt. Take it. She will initially refuse to pay. Mention that you could pay a visit to her family in Marrowind. She will immediately concede and give you the money.
If you just talk with Keerava, you can also convince her by brawling with her. As long as you win, she will pay the 100 gold she owes.
If you have collected from both Haelga and Bersi, then Keevara will give you no trouble. She will just hand over the debt.
Collect Bersi Honey-Hand's debt
Bersi is stubborn as can be. However, he has a soft spot for an ugly Dwarven Urn that he keeps in his shop. Byrnjolf suggests smashing it to get him to go along.
Head out the front door of The Bee and Barb. Turn to the West and go to the next building. This is the Pawned Prawn. Head inside to find Bersi Bersi Honey-Hand and his wife, Drifa.
Inside, talk with Bersi. You will find he cannot be persuaded. You have two choices:
1) Brawl with him
2) Turn around and break the Dwarven Urn with a few attacks or 1 Power Attack.
If you have collected from both Haelga and Keevara, then Bersi will give you no trouble. He will just hand over the debt.
Collect Haelga's debt
Byrnjolf will point out that Haelga is a devout follower of Dibella.
Head to the North of The Bee and Barb. You will find Haelga's Bunkhouse
Haelga, like the others will be dismissive of your attempt to claim the debt. Head inside the Bunkhouse. Head over to the East. On a set of drawers in that direction you will find the Statue of Dibella. Steal it and then talk with Haelga. Threaten to drop it down a well and she will immediately comply and give the money to you.
If you have collected from both Keevara and Bersi, there is a chance Haelga will give you no trouble. She will just hand over the debt.
Return to Brynjolf
Make your way back to The Ratway and return to The Ragged Flagon. Talk with Brynjolf. He will congratulate you on the job and then it is time to be introduced to more of the Guild.