Google Analytics Cheatsheet - learn how to track events, create variables, see pageviews and reference all the documentation.
// ga.js
// [..., category, action, label, value (int), noninteraction (bool)]
_gaq.push(['_trackEvent', 'Videos', 'Play', 'Birthday video', true])
_gaq.push(['_trackEvent', 'Projects', 'Donate', 'Project name'])
_gaq.push(['_trackEvent', 'Accounts', 'Login'])
// Analytics.js
// , , category, action, label, value (int)
ga('send', 'event', 'button', 'click', 'nav buttons', 4);
// [..., index, name, value, scope (optional)]
_gaq.push(['_setCustomVar', 1, 'Logged in', 'Yes', 2]);
// Scope = 1 (visitor), 2 (session), 3 (page, default)
https://developers.google.com/analytics/devguides/collection/gajs/gaTrackingCustomVariables
https://developers.google.com/analytics/devguides/collection/gajs/eventTrackerGuide