Hello info482,
Categorizing transactions such as cheques is a great way to stay organized and simplify your accounting. I'd be happy to help show you how to select various categories when your deposits appear in the bank feed, and how to select categories when you manually enter cheques into QuickBooks Online.
Bank Feed
If you see a cheque deposit in the bank feed, simply click to open the transaction, and select a category from the Category drop-down menu. If you don't see a category listed in the drop-down that would suit your needs, simply click + Add New to create a customized category.
Manually entered cheques
If you're adding a cheque expense to QuickBooks Online manually, click the Plus (+) icon > Cheque. You'll enter a category from the Category drop-down, next to Description. Again, if you don't see a category that's relevant, simply click + Add New to create one.
I hope that helps to point you in the right direction. If you have any questions, let me know.
Have a great day!