non accountant - to do accounting for a 4yr old business

Hi everyone first of Im very much happy to be here, you'll probably see my post on other accounting forums etc., so bear with me. I really need all the help I can get. For starters Im ___ , Im not an accountant but i did had a few subject of accounting during my college days. any how here my dilemma comes, I have been hired by a company which had been running their business for like 4-5 yrs already, they didnt have any accountants or what so ever back then. All they had was just a simple list of all their expenses and income and that's that, so much of it are also gone as some of their records were burnt, fast forward today they have agreed to me to start their accounting book from the point i was hired which is this September as its gonna be a hard time reconciling all records. my problem is i really dont have any idea where to begin. all i m doing now is getting all the records i can such as knowing how much these and that cost which then i'll categorize as assets so on and so fort. to give you an over view of the company COMPANY XYZ is the mother companyand they have 3 business 1. COM ABC - wholesale and retail of bags, shoes, watches etc, 2. COM DEF - restuarant 3. COM 1 , COM 2, COM 3, COM 4 all are engage in selling windows and doors COM 1 - imports their supplies from china - fabricate windows and door using the supplies from china - sells both the supplies to make windows/door from china and sells ready-made windows/ door COM 2&3 – request/buys supplies needed to make windows/doors from COM 1 - fabricate windows and door using the supplies from COM 1 - sells both the supplies to make windows/door from COM 1 and sells ready-made windows/ door COM 4 – doesn’t have their own fabrication, they get their windows/doors requested by buyer from COM 1 OR 2 My question are: 1. Where do I start, what records/cost/price should I get cause right now im just trying to find out the cost/price of whatever is already with the company even before I was hire, such as the computer, furniture and fixture, etc. 2. They want me to basically make separate books for each business, so how should I start, what should be my accounting entries for my beginning balance, cause honestly I don’t know, even before I was hired they already have a working supplies / inventor , they’ve also incurred expenses, as well as made some sales. On the side note, you’ll just probably say to leave my job, or just tell them I can’t do these and just hired a professional accountant. Well I have been hired for a reason, could it be trust, their financial capability or whatever, and I am willing to learn and be able to do this for them. Thank you in advance to all that’ll help