In past I was doing that on spreadsheets but then a friend of mine suggested me to get trained in it through book keeping course online.
I juts followed that suggestion and now I can manage them effectively.
excel is fine for book keeping, I like it, easy to use, I would avoid sage at all costs if you ever get the idea about using that, a nightmare to use IMO and after using it for 6 months I went back to excel lol.
Reply to the thread, titled "Book keeping" which is posted in Business Related on Electricians Forums.