At a minimum, check out the Wikipedia entry on accounting, which will provide you with a good, if largely U.S. oriented, overview of the basic principles.

From the computational point of view, an accounting system, of any size, can be regarded as a structured database with specific reporting requirements.

You should be aware that the most efficient methods of computerised accounting tend to conflict with the tenets of classical double entry book-keeping, as there is a natural bias in software design against maintaining redundant data.

Different organisations resolve this conflict in different ways. At one extreme, there is the use of multiple tables to directly mimic a paper double entry system, regardless of the data redundancy this introduces and, at the other extreme, a single table entry scheme reminiscent of shoebox accounting.