Flash Builder 4 Flex 4 SDK | md5 hash to request a data service feed

I need help.

I just
downloaded the beta for flash builder 4 in an effort to resolve my
latest job challenge.
I watched a few of your video tutorials and am certain flex is the answer to
my prayers.

I have been given the task of creating a swf that has the following
progression:

1. Click submit to login with an email and password.
2. Submit md5 hashes the password sends a request to a server and returns a
response of login success or failure.
3. If login is a a success a widgetKey is returned along with a userID else
failed.
4. Another request during the same session is sent using the widgetKey and
userID to access a getFeed response.
5. The response needs to be parsed into 4 datagrid/xml responses.

*Notes*
The initial page load needs to set a flash cookie and start a session as
well as refresh after 30 minutes.

What I need to know is what I need to test the service. I have names of the
functions along with a url that states the method, widgetKey and userID that
returns a xml response; but, I'm not sure how to pass that info into the
flex data service. I tried a few things like replacing the url for the
HTTPService in some of the flex 3 sample code to no avail. Do I need the PHP
files of the functions or can those be living on the server that Im making
the request to? Do I need the Database connection configuration or can those
also be in the PHP files on the server.

Any and all direction would be GREATLY appreciated!

Thank you so much in advance.