I would bite the bullet and pay someone else. As its very time consuming and a decent book keeper will be up to speed regarding employment changes that can have consequences quite some time down the line. Also, when running a business spending a large portion of your time diverted onto accounts can ultimately be detrimental to you.
Perhaps, for the moment continue to pay a book keeper, ask around & enrol yourself on a new book keeping course, many of them incorporate sage as a standard system. That way when you are ready you will know confidently, exactly what you are doing. HMRC usually end discs out with updates and changes that you need to be aware of, which will keep you up to date.