Click a genre in the table at the top.

Yes, while viewing all DVDs, click the Genre column header.

The Style Swap box allows you to change the layout colors to your liking. It defaults to the manly style, but you can opt to change the style to the not-so-manly style.

Go to the bottom of the page and see if the movie is currently pending or unavailable. If it's not there then I don't have it.

I only lend 1 movie per person.

Movies that have profiles on IMBd link to their respective profile. Some movies don't have a profile to link to.

I used PHP, HTML and JavaScript.

No, well...except for Mike Reid.

To learn PHP scripting and to have an excuse to try things with code (such as this fancy help page).