Concurrent processing - Newbie need information

[Sam Ash]

Hi -

I am presently on an H1B and due to some family reasons I am thinking of moving into an H4. I have the below questions:

1. Is H4 and H4 EAD application submission at the same time possible and is it legally allowed?
2. Any links where I can see what documents to submit for H4 conversion and H4 EAD available?
3. What precautions I should take to ensure there is no break in my work. Like applying for a future date for H4? If so how much in future?

Thanks for help.

Sam.