To Get a Job:
Talk to any Breens you see around the map, and choose the first option. The options under it are promotions.

Example Career:

Jobs:
Job - Required Time And/Or XP [Wage: #]

Sanitation Career:

Jobs:
Street Sweeper - None [Wage: 8]
Sanitation Engineer - 300 XP [Wage: 11]
City Maintenance - 900 XP [Wage: 14]
State Health Inspector - 1800 XP [Wage: 17]
National Sanitation Agency - 2700 XP [Wage: 20]

What to Do:
Pick up garbage, then throw it into a dumpster. After, press E on the dumpster, then choose Empty Trash to throw the trash away and get XP.

Homemaking Career:

Jobs:
Furniture Seller - 1 Hour [Wage: 8]
Furniture Mover - 200 XP [Wage: 11]
Interior Decorator - 500 XP [Wage: 14]

What to Do:
People can press E on you, then choose Use Player, and buy things from you. You can type !stock to see what you sell.

Weapons Dealer Career:

Jobs:
Light Weapons Dealer - 1 Hour & 200 XP [Wage: 11]
Heavy Weapons Dealer - 1500 XP [Wage: 17]
Gun Lord - 3700 XP [Wage: 23]

What to Do:
People can press E on you, then choose Use Player, and buy things from you. You can type !stock to see what you sell.

Cooking Career:

Jobs:
Food Seller - 1 Hour & 50 XP [Wage: 9]
Amateur Chef - 400 XP [Wage: 13]
Gourmet Chef - 1000 XP [Wage: 17]
Sous Chef - 2000 XP [Wage: 21]
Iron Chef - 3000 XP [Wage: 25]

What to Do:
People can press E on you, then choose Use Player, and buy things from you. You can type !stock to see what you sell.

Banking Career

Jobs:
Bank Associate - 2 Hours & 500 XP [Wage: 12]
Banker - 3500 XP [Wage: 19]

What to Do:
People can press E on you, then choose Use Player, and deposit / withdraw money from you.

Medical Career

Jobs:
Med Student - 4 Hours & 200 XP [Wage: 10]
Med Resident - 500 XP [Wage: 15]
Doctor - 1200 XP [Wage: 20]
Surgeon - 2300 XP [Wage: 25]
Chief of Surgery - 3400 XP [Wage: 30]
Police Medic - See Police Career

What to Do:
Press E on people who are hurt, then press Your Actions, and heal them. Don't farm XP though, because you can get banned for that.

Gangster Career

Jobs:
Gangster - 1 day and 1k XP [Wage: 12]
Mafia Member - 1550 XP [Wage: 19]
Mafia Lord - 5100 XP [Wage: 26]

What to Do:
Kill rebels with crime for experience:
Crime (>= 1000 && <= 1499) = 1 XP
Crime (>= 1499 && <= 2999) = 2 XP
Crime (>= 2999 && <= 4999) = 3 XP
Crime (>= 4999 && <= 7999) = 4 XP
Crime (> 7999) = 5 XP

EXCLUSIVE JOBS

Police Career:

Jobs:
Police Recruit - 50Hrs [Wage: 15] (Accepted Application - Forums)
Police Officer - 1000 XP [Wage: 20]
Police Chief - 2000 XP [Wage: 25] (Can switch to Medic)
Police Medic - 3000 XP [Wage: 30] (Can switch to Chief)
Police SWAT - 4000 XP [Wage: 35]

What to Do:
Arrest people with crime and pull them to jail. Read the cop guide for more.

Firefighter Career:

Jobs:
Firefighter - 420Hrs & 1000XP [Wage: 30] (Accepted Application - Forums)

What to Do:
Put out fires, disarm, diffuse and dispose of bombs.

Political Career:

Jobs:
City Official - 10 Days [Wage: 20]

What to Do:
Nothing really, you just get a lot of wages.

VIP Career:

Jobs:
VIP - Donors [Wage: 20]

What to Do:
Nothing really, just for donators.

Management Career:

Jobs:
<[RCS]>Management - Management [Wage: 100]

What to Do:
Be awesome - Other than that hold the server down.