CLEP help

[ambitious]

hi,
i have to do the following CLEP credits:

English Composition ,Biology,Introductory Psychology,Introductory Sociology,College Algebra,College Mathematics,Natural Sciences,Introduction to Educational Psychology

Could anyone help me with the following:

I am confused about how much time these will take?i wanted to know which ones are easy n which ones r tuff so that i can combine them.....n approx how many days to allot for each?....n which books to refer?....i have been searching the net and in some places they say one book is enough and somewhere they say 2 specific books are a must for subjects like college maths,college algebra etc
can u guide me?
thanks