Iam a nigerian living in nigeria.How can i get admission or scholarship to study in united states of america?
First step is always to take the TOEFL exam.  It doesn't matter that you know some English; they will require you take the TOEFL for proving your skill there.\n\nYou need to spend a good bit of time online researching universities, and finding which ones would best fit your desired course of study.  \n\nYou will also, after seeing your TOEFL score (at least 500 to 550), need to take the SAT exam before admission.  This is also useful for scholarship -- if you do very well on it (1300 or higher out of the old scoring with highest at 1600) then you *may* find universities which will offer part of a scholarship. \n\nIn terms of cost, it is always best to remain in your own country.  The schools in Nigeria are pretty good from what I've heard.
You may want to consider grants from private foundations.\n\nFor private grants, you may want to check the Foundation Center's Foundation Grants for Individuals Online http://gtionline.fdncenter.org . It's a subscription based website ($9.95 per month) and their opening blurb only says that the database is ideal for "students, artists, academic researchers, libraries and financial aid offices."