Need urgent help for visit visa (Bangladesh)

[bdpeople]

I will apply for my husband for a visit visa.I allready applied for the sponsorship but in the meantime i want to apply for this visit visa (less than 6 month). Can anybody please tell me which document (supporting) i need to show? How much money i need to show?
Is there any cover letter and how it will be? any sample?
I am sure many of us went throught this process and got the visit visa. Can any of you give me the suggestion please?

Thanks a lot in advance.