Documents required for tier 2 visa

[pkun6]

Hi,

I need to apply for tier 2 visa ASAP. I got the CoS reference number but I don't have any CoS document print.
I have filled the application form online and taken the printout with me. My CoS covers my maintenance funds.

My questions -

1. What documents I require other than my printed application form and my degree certificate (English language test proof) for visa application file ?
2. Do I need a cover letter for UK visa ?
3. I am applying from bangalore. Can some one please share some experience for UK tier 2 visa application file (if any).
4. Do I need CoS document or does the reference number only should work peacefully ?
5. Does the documents need to be in proper sequence or will someone at VISA office will ask me to put it in sequence at that time only?
6. Even though my employer is covering for maintenance funds, submitting my 90 days bank statements (covering the maintenance funds) will be helpful ?
7. Do I need CoS printout ?
8. Do I need the offer letter from my employer, stating my salary and joining details etc ?

Any answers/experience on the above will be a great help for me or any newbies like me in future.

Regards
Prav