If I invite someone with Accountant access are they able to edit my records? If so, is there any audit log where I can see what changes have been made?

Welcome to the Community, @BusinessGuy.

When inviting an accountant, make sure that your accountant must use have their own QuickBooks Online for Accountant account. Once they accept the invitation, your company will be added to their client list. 

Your accountant can follow the steps on how to add a client to QuickBooks Online Accountant.

If they don't have a QBOA account, they'll need to sign up so they can access your account. 

If everything is all set, they can now edit records in your account.

And here's how to check the changes they've made:

1. In the upper right of your screen, click the Gear icon.
2. Choose Audit Log.
3. You may use the Filter to easily look for the transactions.

You may also check on how to add and manage users in QuickBooks Online.

Get back to me if you have any additional questions about inviting an accountant with your QuickBooks Online account. I'm just a post away.