Newbie plugin programming problem

I’m trying to write my first plugin, specifically the administrative screens (to enter data). I’ve got the menu and my page appearing. On my page are three links “edit foo”, “edit bar”, and “edit baz”. What I want to do is to click on “edit foo”, reload the page with the same links at top, and a form beneath to edit foo.

I can’t figure out how to constructthe link for “edit foo”. When I say:

<a href="?page=<?php echo $_GET['page']; ?> &edit=foo">Edit foo</a>

I get an error that it can’t find my page. If I remove the &edit=foo, the link works but it only reload the same three links.

Can someone tell me how to do what I want or show me the way I’m supposed to be doing it? The Admin pages will ultimately let me do CRUD (Create Read Update Delete) against my tables in the database.