The two fundamental books of accounting are the journal and the ledger. The journal is the first book where transactions are recorded in chronological order, and the ledger is the second book where transactions are classified and summarized. In the journal, transactions are initially recorded using debits and credits, while in the ledger, each account has its own page, and entries are made in a specific format based on whether they are debits or credits. Together, the journal and the ledger provide a complete record of all financial transactions for a business or organization.