David
Dave is right - especially about researching your market
I would add is that COSHH is quite straightforward - if you go onto the HSE website (just type HSE into Goggle) and there is load of staff on COSHH (and all things Health and Safety!) - it is a great site and full of useful info. You could also look at COSHH Essential (which I think is run on behalf of the HSE) which is also useful. If you need any further info everyone here is friendly and glad to help, or feel free to email me. If you are desperate I am sure that I could find something on a powerpoint which may be of use but try the HSE Website first.
Also, if you are employing people do not forget Employer's Liability Insurance!
Finally CRB checks are great for marketing, but can take time to receive back. Personally I would rather do them than not - but you have to be prepared to sometimes employ someone whilst you are awaiting the CRB check to be returned - which can make things complicated while you are waiting and if it returned with a positive result.
Hope this helps
Nick