Welcome back, glad you're enjoying the game.
The market board, when viewed from your room, it sort of not-ituitive. Good news is there's only so many buttons to worry about.
Your room has 2 vault slots. The smart adventurer will place a box or backpack in them to increase storage space. Those slots are also your For-Sale slots. Items for sale in there will appear to all players when they search the Broker. Open the market board, select Vault, and begin assigning prices.
TIP: Browse the market first to see what others are selling the same items for. Adjust your prices as you like to stay competitive. You can check/uncheck items for sale if you want to sell only a few items in your vault. You can't move items back and forth from your personal intentory to your vault from that merchant window. You must open your own bags and the vault slots then frag/drop items back and forth.
TIP: You can't remove a for-sale item from your vault. Go to the merchant window, make it "Not For Sale", then you can move it. (it won't be red anymore in the vault slot) You can also sell items in your personal bags, but they will only show on the Broker when you are in your room. If you leave, they will come off the broker list. When you log out, items in your vault will stay on the list for 24 hours. To get them back on the broker list, simply log back on.
Here's a few crafting links that might help you out:
SOE Official Tradeskill Forum How-To of Crafting All The Recipies You Can Stand Remember, to start crafting, you need to go into the crafting zone in any town, usually your home town. Being a low level crafter, you can only start in the wholesale zone (the only one where the NPC will let you in).
You have a note in your inventory about tradeskilling. Examine it to get the list of wholesale zones in Qeynos.
Talk to the NPC inside to start some quests to craft different items, gain tradeskill exp, and gain some items.
What server are you on, by the way?