get in touch with your local tax office and ask about a self assessment work shop ( it's free). 4hrs out of your life well worth it.
if you do the work shop it will give you an idea of if you could do it yourself or if you want an accountant
but to answer your question pretty much anything that is for the business can be claimed back unless it is something you would use anyway (like food).
you can claim, cleaning material, uniforms, fuel, advertising, stationary, etc, etc, etc.
