You can either opt to claim a % of your utility bills based on the business use, or an easier and more popular method is to claim a set amount per week, for example £8. You can claim tea and coffee on top of this, again only that used whilst running your biz.
If you have a motor vehicle you use for your book keeping business you can claim capital allowances if it is a business asset, as well as running costs including petrol and repairs.
As with any training course you undertake, if what you are learning is a new skill then you should really include the cost of the course as an intangible asset in the balance sheet. If it's simply update training, perhaps if you already have book-keeping experience, then you should be ok to include the cost of the course in the profit and loss account.
