Here are some resources in biology that students may use to help benefit themselves in learning and understanding:

Wikipedia
http://www.wikipedia.org/
Wikipedia is a free reference Web site where it is written collaboratively by people all around the world.  It allows anyone to edit, correct, or improve the current information throughout the encyclopedia.  This site provides great information for students.  I highly recommend the use of this site.

Dictionary
http://dictionary.reference.com/
This site provides students with the ability to look up words that they do not understand.  It also provides links for students such as thesaurus, reference (encyclopedia, almanac, and web search), language resources, word of the day, translator, tools, other dictionaries, bookstore, and much more.  Students should take advantage of using a tool like this. 

Biology Resources
http://www.educationindex.com/biology/
This site provides information on biology resources that students are able to access.  This is great for students who are doing research projects or looking to increase their own knowledge and understanding in a particular area of biology. 

Biology Resources and Links
http://naturalsciences.sdsu.edu/links.html#anchor39582
This site provides students with a various amount of resources.  This site provides resources such as biology education resources, biology and other sciences lesson plans, biological sciences libraries, miscellaneous sites dedicated to biology and science education, organizations involved in science education, natural history museums and nature centers, public zoos and wildlife parks, public aquariums, and ecology links.  Just by clicking one of these links can provide you with much more resources for students to use. 

Biology Resources
http://www.ornl.gov/info/library/biology.html
This website provides students with general biology resources such as dictionaries, funding sources, databases, and government resources.

School Science
http://www.schoolscience.co.uk/content/index.asp
This site can be useful for students in all sciences such as biology, chemistry, and physics.  It provides resources for students ranging from 11-18 in these specific science subjects.