Hi, this may be a "noob" question but anyways...
I'm doing quests for Big Helende and I have done everyone but one, I want to start getting quests from Gentleman Jim Stacey but for that I need to be a captain.
When I ask for advancement Big Helende says "No one questions your lojalty, but you have to train your skills to be Adam the Captain", which skills in particular do I need to train and how much, I've tried training the skills she offers training for but that doesn't help, anyone know what I should do?

You need to have the Guild's favored Skills and Attributes at a certain level.

Favored Skills:
* Acrobatics
* Light Armor
* Marksman
* Security
* Short Blade
* Sneak
Favored Attributes:
* Agility
* Personality

In your menu, scroll down to your list of Factions. Hover over the Thieves Guild text, and you will see what level you need to raise your Skills and Attributes to in order to gain more advancement.

Example: to be named a Captain, you need your Agility and Personality at least 32, as well as one favored Skill at least 60 and two others at least 20.