User guide
How the whole thing works
One page per part of the product, in the order most people meet them. Each one covers what you can do, how it works in practice, and the limits worth knowing before you rely on it.
4 pages, and growing — written by the people who build it.
Sales
Quoting, invoicing and the people you sell to.
Money
The books underneath it all — accounts, payments, tax.
Stock
What you hold, where it is, and what it is worth.