Build Excel Sheet

I need someone to help me build a spreadsheet "form" that pulls data from another spreadsheet. For example, on the main form, if I enter X in cell B5, then I would like the form to auto-fill cells B6, B7, B8, and B9 with data from another sheet (Sheet 2) that is associated with X. If I enter Y in cell B5, then I would like the form to auto-fill cells B6, B7, B8, and B9 from the data associated with Y on Sheet 2, and so forth. I would also like cell B5 (and possibly other cells) to have a drop-down menu with pre-selected choices (also from Sheet 2). It is is very important that it be set-up so that it is easy to add or change data in the database sheets. For example, if a new item is added to the data which form the drop-down menu choices in B5, then everything should still work.