why can't I access the library site in Cameroon W. Africa ? I thought the library could be accessed wherever in the world with internet capability
I do not know why you cannot access the National Library of Cameroun (or Cameroon) on the Internet. I found no website.
But, you can find information about Cameroun related web sites at this web site mantained by Stanford University. http://library.stanford.edu/depts/ssrg/africa/camer.html
You might try searching to see if any of the universities in Cameroun have a library you can access. I could not find one.
Also, you might try searching for any library outside Cameroun with a large collection about West Africa.