Seconding this, the GnuCash manual is fantastic. The principles of double entry accounting are very simple but if you're not used to thinking in those terms it

Seconding this, the GnuCash manual is fantastic. The principles of double entry accounting are very simple but if you're not used to thinking in those terms it can sometimes be a little confusing how to fit real life scenarios into that framework. The GNC manual has a lot of helpful explanations and examples.