On the Clan menu it is possible to see all of your Weapons and Warriors. If you bought them with coins you can sell them off or buy more. Along the top of the page are menus which allow you to view items by category and strength.
Visit your Blacksmith to craft new and better items from any unused Gifts and low-level items that might be cluttering up your clan inventory. The Blacksmith has recipes for new equipment, all you have to do is find the components for them. However some recipes are hidden, and have to be discovered either by trial and error, or by getting another Viking in the know to tip you off.
Some Weapons and Warriors have an Upkeep cost, which reduce your total income. You can purchase and sell these warriors and weapons from the Clan menu and where possible use the Blacksmith to reduce the drain on your income by converting upkeep items into regular items.
Although they can be a big help with your defence Legendary warriors can prove to be a significant drain on your income so keep an eye on how many you have and make sure it never exceeds the amount you actually use by too much.