Wordpress Navigation Help - php

Question

I am working on a site that calls the categories of a wordpress page and displays them in the right-side navigation using a php call. I am new to php and web programming in general. Is there a way I could split the categories into two sections using a particular php call or perhaps an if-loop.
Essentially, I want to display particular categories under custom sub-headings to better organize the site. Any help, I'm currently using the following script to display my categories:
<ul><?php wp_list_categories('show_count=1&title_li='); ?></ul>
Here is my site for reference: http://www.merrimentdesign.com

Answer 1

Try using your code above twice. Each time, you can use the other function arguments to limit the output to certain categories. See http://codex.wordpress.org/Template_Tags/wp_list_categories for the various ways to customize the output of the function.
For example you could use:
<ul><?php wp_list_categories('show_count=1&title_li=&child_of=100'); ?></ul>
// where 100 is the parent id of all of the categories you want to print.
<ul><?php wp_list_categories('show_count=1&title_li=&exclude_tree=100'); ?></ul>
// and then show everything, but children of 100
Or simply use the first string multiple times specifying different parent ids each time.

Answer 2

By far and away your best option is to use the new menu functionality within WordPress. It's dead straight forward to set up in your theme:
add_theme_support( 'menus' );
add_action( 'init', 'register_my_menus' );
function register_my_menus() {
register_nav_menus(
array(
'public-menu' => __( 'Public Menu' ),
'sidebar-public-menu' => __( 'Sidebar Public Menu' ),
'sidebar-members-menu' => __( 'Sidebar Members Menu' ),
'sidebar-staff-menu' => __( 'Sidebar Staff Menu' ),
'footer-menu' => __( 'Footer Menu' )
)
);
}
place that in your functions.php file (and obviously change it for your requirements).
Then in your template file - probably sidebar.php you'll want something like:
<?php wp_nav_menu( array( 'theme_location' => 'sidebar-staff-menu', 'container' => false ) ); ?>
And then go to the back end of WordPress (your wp-admin) and then go to Appearance > Menus and voila you're able to drag and drop your categories to your heart's content!
Helpful link: http://justintadlock.com/archives/2010/06/01/goodbye-headaches-hello-menus
Read that, Justin Tadlock is awesome.
Good luck.