Custom Theme Question

I'm trying to throw this together w/tables, frames, and php but I keep hitting a wall. Let's say I create a new theme, or template, or whatever you want to call it. It's basically a large image sliced to fit the html tables. I'll use the user block as an example. I place the form script within the table, but when I test it, I got a security error. Well then, I moved this theme to my templates folder. I got the security thing to stop, but now I get a login.php not found on this server. Go figure! Anyway, if someone could tell me how to put a functioning login form into my custom theme, that would log me into my database, I'm pretty sure I can figure the rest out. I'm hoping you understand what I'm trying to do here. If not, the attached image may help.
On a side note, I know there are alot of resources for themes out there, but photoshop is one of my hobbies, so this is something I need to learn on my own. With the exception of a few pointers from you guys <img>
[flash=,:2runzbh2]http://i63.photobucket.com/albums/h129/Threat009/Custom-Theme.gif[/flash:2runzbh2]
On a side note, I know there are alot of resources for themes out there, but photoshop is one of my hobbies, so this is something I need to learn on my own. With the exception of a few pointers from you guys <img>
[flash=,:2runzbh2]http://i63.photobucket.com/albums/h129/Threat009/Custom-Theme.gif[/flash:2runzbh2]