Please please PLEASE can someone explain the binding system in dungeonerring to me

Basically I got some dungoneering bot and it told me to 'bind to weapon of my choice'.

How do I know what one is better and where do I get a better one?

Also what does 'binding' do and how many items can I 'bind'

When you bind an item you keep it with you through all floors, it doesn't disappear when you are done.

Best to bind is the highest weapon you can wield. If you examine, it will tell you what tier it is.
Depending on your level, is how many you can bind.