Biology was my first clep and i was so scared starting with it.. read the guide in the exam section...

I used:
1) Biology smart as a warm up
2) Cracking AP biology is amazing
3) IC
4) Peterson`s exams

keep in mind if you have to take natural science too, make it straight after Biology.
Good luck

Edit: for now see how good you are with the peterson`s exams..

__________________
CLEP
6 Biology 65
6 Natural Science 64
6 College Math 63
3 College Algebra 62
3 Precalculus 70

DSST
3 Into. World Religion (rev2008) 425
3 Astronomy 58
3 Into Computing 460

Class
4 College Physics II B+

TOTAL = 37
Finished , Thanks InstantCert for all the support.

Trust in Yourself, You Can Do it...