When it is your turn, the actions panel will show all of the actions that you can perform. Some care must be exercised, as some actions can only be performed once per turn, and other actions can only be performed in strict sequence.
Procedure 2.1. Simplified turn sequence
Roll the dice.
Optionally trade with the bank, or other players.
Optionally build roads, settlements, and cities. Optionally buy development cards.
Finish your turn.
You may play one non-victory point development card at any time during your turn, even before you roll the dice. You may play as many victory point cards as you like at any time during your turn.
As soon as you have built a road, settlement, or city, you will not be able to trade for the rest of the turn. Likewise, if you buy a development card, you will not be able to trade for the rest of the turn.
When the dice are rolled, they are added together, the total determines the resources that each player collects during that turn. In the center of each land hex (except for the desert) is a number. Whenever the dice roll matches the number in the hex, all buildings on the corners of that hex will collect resources of the type generated by that hex.
Settlements collect one resource, and cities receive two resources. If a player has multiple buildings on a hex, each of those buildings will collect resources.
The hex containing the robber never generates resources.
If you roll 7 on the dice, all players with excess resources must discard them, then you must move the robber.
If you roll 7 on the dice, all players holding more than 7 resources must discard half of them. The discard resources dialog will be displayed for all players who must discard.
You must choose the resources to be given back to the bank.
Once all players have discarded their excess resources, the player who rolled the 7 will have to move the robber.
The robber begins the game in the desert, but can never be moved back into the desert.
If you roll 7 on the dice, you must move the robber to a new location on the map.
Whenever you play a soldier development card, you must move the robber to a new location on the map.
Once you have moved the robber to a new hex, the robber will steal a random resource from another player who has a building on that hex. If there are multiple potential victims for the robber, you will need to choose the victim by selecting one of the buildings on the hex. When the robber steals the resource, only the players involved in the transaction will be told which resource was stolen.