Letting out individual rooms advice wanted

Tenancy Deposits

I wonder if someone could offer me advice to let individual rooms out. It is the first time I have let out rooms myself, so any advice and your experiences would be greatly appreciated.

Currently I have a 3 bed house recently redecorated, which I decided to let out each room individually.

I have advertise on Gumtree and SpareRoom, is there any other particular good website that are useful to let out individual rooms?

Someone came round yesterday to view and reserved a room. I have taken a deposit of £300, and I have gotten him to fill in a tenancy application form. Which I have taken details of his current address, DOB, NI number, current employer, current landlord , character reference and a emergency contact. Anything i missed?
I have not got hold of his Passport/Driving license or 3 months bank statements yet, is it okay to get it later from him?

I have just used RLA Tenant credit check and currently awaiting result. How long does it take? Is there any other good referencing site? To obtain employer or landlord reference, should i call them and ask for the protential tenant reference over the phone?

Is it the best way to sign the tenant on a 6 months AST, or other options?

Currently I have advertise the rooms to be excluding bills. What is the best way to manage the bills for the tenants?
Is it normally the landlord pays for the bills first, then charge the tenants who will live at the property?
Also is it best to calculate the know bills first (eg Council Tax, Water, TV License, Broadband)?
And charge the Gas/Electricity later? How much do you estimate Gas & Electricity usually cost each month?

Any other cautions or things I need to becareful about?

Thanks in advance