Caravan

You can join a caravan as a guard and earn caps and xp by protecting it from wasteland threats.
There is a Caravan coordinator in Hub that know where certain caravans go, where they are now and where they are currently headed.
To join a caravan as a guard, talk with the Caravan Master NPC (guy with Combat Armor and 250 hp) when he is in town.
You have to be at least level 9 to join a caravan.

Caravan coordinator in Hub

Caravans

• Crimson Caravan
• Far Go Traders
• Van Graffs
• Stockman's Association
• Goods'n'Go
• Hang Transportation
• Gun Runners

Crimson Caravan

Hub<->Shady Sands<->Broken Hills<->Vault City<->New Reno

Far Go Traders

Hub<->San Francisco<->Redding<->Modoc<->Vault City<->New Reno

Van Graffs

Klamath<->Den<->Redding

Stockman's Association

Redding<->New Reno<->Shady Sands<->Junktown<->Hub

Goods'n'Go

Gecko<->Broken Hills<->New Reno<->Shady Sands

Hang Transportation

Hub<->New Adytum<->San Francisco

Gun Runners

Gun Runners<->Hub<->Shady Sands