How to start accounting an existing business

gentlemen
i have a situation. hope i will get the best sollution.
i am going to work as an accountant in an existing business which had done
accounting never before.so what are the initial steps that i have to take if
i start accounting?
cctv installation is the business. apart from purchase they sometimes buy the 
cctv components and make cctv. in which category this belongs...,manufacturing or 
trading?