To start, Wells Fargo provided the best training I've ever received. They focus on role-playing and overcoming difficult scenarios to prepare you for the rigors on your first day. After that there's typically a Lead Teller, a Service Manager, and a Branch Manager at every Branch, each of which acts as a mentor. Wells Fargo hires relatively down to earth Team Members who enjoy being your friend, so asking for help isn't an issue. With that said, it is a customer-facing role, so be prepared for lines, rushes, and the occasional aggravated customer. Wells Fargo likes to see Team Members start from the bottom (as a Teller) and move up through the roles. Most Branch Managers, District Managers, and Area Presidents started as Tellers. Don't be surprised if one your first day they ask you what you want to do and how you plan to do it. Lastly, Wells Fargo provides constant supplementary training from topics ranging to Leadership and Communication, to Loss Prevention, Career growth, Product Knowledge and more.
I believe it was a month. They'll put you on a computer in a backroom and you basically go through simulations of all the transactions that you go through. How to process checks, how to convert currency, how to deposit, etc. They basically teach you how to use the teller software.