Past earnings: Receiving part of income as dividends.

[MyHSMPApplication]

Hi,
Can any one let me know as to what are the documents along with their formats that are to be submitted as proof when one is receiving part of income as dividends.
All I have is the
1.P60 for the year 2006-2007
2.Bank statements which shows the abrv company name.
3.A statement from the company in its official letter head stating the amount of dividends received on a monthly breakup along with the tax creding for each month. It also shows the total dividends received for the whole year. However there isn't any stamp/seal of the company neither there is any signature from the authorised person.

Do let me know what other document should one submit?
Is it a must for me to file my returns with the IRS?
Cheers
PG