You can learn Urdu via the Internet for free. The site Language Learning Advisor links to several other sites with Urdu learning software, including basic Urdu lessons from the South Asia Center at Syracuse University; Ukindia's Urdu-reading lessons; and BYKI's Learn Urdu programs.
To learn to understand Urdu fluently, practice by listening to free Urdu radio stations, such as Online Urdu radio provided by the BBC and by practicing with a speaking partner through MyLanguageExchange.com, where you can speak or text with native speakers.
Practice reading in Urdu with free online reading sites, including Urdustan.com, a literature site; the Urdu Poetry Archive, the Urdu Poetry Forum and Urdu Poetry Portal. Several other links to Urdu magazines and newspapers can be found at Omniglot: Urdu.