Adding items to your 'helpbot store' list is easy and done entirely ingame.
First you need to join the 'helpstore' channel by using the following command:
/tell helpbot store join
You can now simply add your items by posting them in the 'helpstore' channel.
[Helpstore] User has joined the channel
[Helpstore] User: Combined Awesomeness Kyr'Ozch Epeen OFAB Improved Candy
Once you're done ingame, visit this web page and use the form above.
Setting a price
You can include a price for your items in the generated shopping list. Doing so, is easy.
Instead of simply posting all your items in the 'helpstore' channel, do it as following:
Post 1 item per message and simply type your desired price after the item and hit 'enter'.
Clearing your items list
Before creating a new 'helpbot store' list, you need to clear out all previous entries.
You can do this with the following command:
/tell helpbot store clear
After 7 days, all items still in your store will be removed automatically.