Jeremy Ernst has created a very good introduction series to Maya UI creation with Python on vimeo:

Video 1:https://vimeo.com/42848594
Video 2:https://vimeo.com/43167571
Video 3: https://vimeo.com/43948657
Video 4: https://vimeo.com/44707576
Video 5:https://vimeo.com/45590131
Video 6: https://vimeo.com/45980607
Video 7: https://vimeo.com/46452342