Here is a large lists of most of the important commands:

/afk - Announces you are afk
/back - take you back to the last place you teleported from (or death if you are Citizen+)
/bal - shows your balance (or balance of other players if a name is provided)
/baltop - Shows the top richest players on the server
/help - Get info and commands
/home <name> - teleport to your set home
/ignore <player> - ignores a player in game
/mail <player> <message> - sends a message to specified user (if offline, the player can see this message when they log in)
/me - emote / role-playing command - sends a message with no prefix (ie; /me laughs)
/msg <player> <message> - sends a private message to another player
/pay <player> <amount> - give a player money from your balance
/r <message> - reply to the last /msg you received
/recipe <item> - shows how to craft the specified item
/seen <player> - Shows a player's last login if offline, or time online if online
/sethome <name> - adds a personal warp point that you can warp to (more homes are added for donators)
/sit - sit down
/suicide - commit sudoku (RIPperoni)
/vote gui - open the voting interface. You can use this to vote and earn rewards.

/spawn - teleport to the server spawn location
/warp <name> - warp to a server set warp location
/warplist - list the warp names
/arm tp shop<#> - teleports you to the specified shop region (ie: /arm tp shop69)

/tpa <player> - sends a request to teleport to another player
/tpacancel - cancels the current teleport request
/tpaccept - accepts a pending teleport request.
/tpahere - sends a request to teleport another player to your location
/tpdeny - deny the current teleport request

/pv <#> - opens your player vaults. (6x9 chest per vault, only available to donators)

/qs buy - set your shop to buy the item
/qs sell - set your shop to sell the item (sell is default)
/qs price <amount> - changes the buy / sell price of the item
/qs find <item> - finds the closest shop that sells the specified item

/f create <name> - creates a faction
/f invite <name> - invites a player to join your faction
/f join <faction> - command to join a faction
/f bank deposit - transfer money from your balance to your faction so you can claim land
/f claim - claims the chunk you are standing in
/f sc - Toggles show chunk mode (particle effects outline chunk borders)
/f map - shows a map of nearby claimed land and what faction claims it (each character is a chunk and your current chunk is the center)
/f sethome - sets your faction's home
/f home - teleports you to your faction's home
/f who <faction> - see details about a faction (if no faction is entered, it defaults to your faction)
/f open <yes/no> - sets if anyone can join your faction (If set to no, they can still join via invite)
/f global - toggle between global chat and faction chat
/f chat <mode> - change chat mode (alliance, faction, mod, public)
/f perms - change what players are allowed to do in claimed areas
/f owner <player> - allows a player access to build on a claimed chunk
/f upgrades - upgrade faction perks
/f help - more commands

Feel free to contact me with commands that should be added to this list