CSE stands for the Council of Science Editors. (Formerly it ws CBE— Council of Biology Editors.) This is not a frequently used style, but sometimes instructors and journal editors will ask for it.
Most of the items you will need to cite in biology classes will be journal articles. Of these articles, most will be available online (even if Geneseo doesn't have a subscription to them).
If you need to cite a book or a print journal article, consult the complete guide to NLM citation style, available online.
Author AA, Author BB. Article title. Journal Title [Internet]. Date of Publication [Date of Citation]; Volume Number(Issue Number):Pages. Available from: http://journalurl
Piwowar HA, Day RS, Fridsma DB. Sharing detailed research data is associated with increased citation rate. PLOS ONE [Internet]. 2007 [cited 10 April 2013];2(3):e308. Available from: http://dx.doi.org/10.1371/journal.pone.0000308
Rubenstein DR, Lovette IJ. Reproductive skew and selection on female ornamentation in social species. Nature [Internet]. 2009 [cited 11 February 2009];462(7274):786-9. Available from: http://www.nature.com/nature/journal/v462/n7274/full/nature08614.html
Terauchi Y, Takamoto I, Kubota N, Matsui J, Suzuki R, Komeda K, Hara A, Toyoda Y, Miwa I, Aizawa S, Tsutsumi S, Tsubamoto Y, Hashimoto S, Eto K, Nakamura A, Noda M, Tobe K, Aburatani H, Nagai R, Kadowaki T. Glucokinase and IRS-2 are required for compensatory beta cell hyperplasia in response to high-fat diet-induced insulin resistance. Journal of Clinical Investigation [Internet]. 2007 Jan 2 [cited 2007 Jan 5];117(1):246-57. Available from: http://www.jci.org/cgi/content/full/117/1/246