a high-level overview -
1. get sql 2005 express - <a href="http://goo.gl/59WLi">http://goo.gl/59WLi</a>[<a href="http://goo.gl/59WLi" target="_blank" title="New Window">^</a>]
2. get sql 2005 express management studio -
http://goo.gl/YhbX2[
^] (probably just get the 32-bit one - no x64 in the download name)
3.install sql 2005 express - use a default instance with mixed auth - windows and sql. set a strong "sa" password.
4. backup your db from your dev machine and restore it onto your new sql server (using remote or local sql server management studio).
5. the default instance will not have a suffix after the computer name...so your connection string should just specify your server. i'm guessing you have no centralized authentication and that you are using sql auth in your connection string.
does this help?