Check out how your prospective professions present themselves to the world - sites often have job listings and other information for people in the field. Many have special membership for students.
Submit your suggestions!
Two quarterly magazines from the American Society for Microbiology,
Small Things Considered - an engaging blog about microbes, and more by Moselio Schachter, on the ASM website.
[no longer maintained - links may not work] The Microbial World - a website from a professor at University of Edinburgh, Scotland. See in particular the List of Themes (AKA, Other Pages On This Site) for pages about narrower topics including profiles of specific microorganisms and their impacts.
Microbes.info is a microbiology information portal with lots of useful links.