Video can be found [HERE](https://www.youtube.com/watch?v=OsTOCY-AqXs):

0:00 Intro

0:20 Why use a wallet?

1:40 How to start?

2:26 Install the Polkadot.js browser extension

4:24 Create a wallet account & seed phrase security

7:36 Substrate addresses

9:10 Deriving another wallet account

10:10 Allowing a page to see your addresses

11:15 First look at the Polkadot.js Portal

12:34 How to prepare a send transaction

15:10 Polkadot.js Metadata Update

17:20 Sending tokens from Alice to Bob

18:23 How to learn more

https://twitter.com/ruitao_su/status/1208305894083022848

For a complete walkthrough of PolkadotJS wallet extension and usage.