Book-keeping for my Small Operation

So I would say that my activities are small, it is really just me at the moment. I hope to use the services of an accountant for:

1. personal tax return (I have to be a provisional taxpayer as I am a member of a CC)
2. company tax return

So I have to figure out how to keep record of all costs and transactions myself. I always want to try and use open source software where I can, so I am trying out GNUCash, which from an accounting perspective appears sound, and so far is easy to use. The only problem is that I know so little about keeping books so I am reading help files and trying to figure this out as I go.



Wish me luck!