start with 13-17 lb.s pale malt of your choice. use a lb. of flaked wheat, 1-2 lb.'s of crystal/biscuit/aromatic malt. use some citrussy hops combined with more(!) hops, of your choice, IPA's are so noticeably hoppy that you should choose ones you like the best. american ale yeast is my favorite for IPA's. thats bare bones. play with it to make it more interesting.
edit: you can find the guidelines on the BJCP page.