This video is a demonstration of entering expenses in Wave.

0:00 Intro
0:27 Connected Bank/Credit Card accounts
1:12 Review of transactions page with bank connection
2;12 Chart of Accounts overview
3:26 Adding an account to chart of accounts
4:24 Adding transactions using bank connection
10:29 Adding manual transactions
16:37 Financial report overview

Other videos mentioned:
Assets vs Expenses:    • Assets vs Expenses  

Importing transactions from bank website:    • Importing Transactions in Wave Apps  

Account reconciliation:    • Wave Apps - Reconciling Bank and Credit Ca...  

See the following page from IRS website about the "de minimis safe harbor election" which is related to the computer purchase example in the video:
https://www.irs.gov/businesses/small-...

Disclaimer: This video is not intended to replace advice from your CPA or tax preparer.