Purchase Order Form

Hello Asp.net,
I have been tasked with making a purchase order form.  Currently we have a sytsem that was made in Microsoft Access.
This form has to carry out a number of functions and I am looking for a guiding hand to help me ensure that it manages to do this.  Making a PO Form is a little but over and above what I know of ASP and there is no better time to learn than the present.
The form has to do the following:
Pull user names into a drop down menu for selection Take user inputted "required by" date Populate a dropdown box name with supplier names and on selection of a supplier name populate the text input boxes below with the suppliers address. !Important! Take a currency selection Allow users to add stock items to the PO from a stock list. ...