The typical actions are here:
http://codex.wordpress.org/Plugin_API/Action_Reference
Specifically, the order is a bit like this:
# plugins_loaded
# sanitize_comment_cookies
# setup_theme
# load_textdomain
# after_setup_theme
# auth_cookie_valid
# set_current_user
# init
# widgets_init
# register_sidebar ******************************
# wp_register_sidebar_widget
# wp_loaded
# auth_redirect
# wp_default_scripts*
# _admin_menu
# admin_menu ****************************
I want admin_menu to run before register_sidebar.
Or register_sidebar to run after admin_menu
Is there anything I can add to functions.php to make this happen?