Scioly.org

this will be our school's second year in science olympiad.
does anyone have any tips for disease detective?

Check out the wiki! http://scioly.org/wiki/Disease_Detectives
It has a lot of basic concepts as well as what material is covered by Divisions B and C.

However, my personal recommendation:
Start reading the Morbidity and Mortality Weekly Report (MMWR) every week at http://www.cdc.gov/mmwr/.
Even if you don't read the full text, at least skim over each week's report to get a feel for terminology and how epidemiology works. Plus, you might just see one of the MMWR's topics on a test during competition.

Does anyone know what to do??

The Event Format section of the Disease_Detectives Wiki has a good outline of the epidemiological concepts covered in both Div B and C.

The wiki also has basic reviews of some of the major topics; it's a good place to start your own research!

anyone have any good resources?

http://www.cdc.gov/excite is the main one. There actually isn't that much to know for this event...the wiki and excite pretty much cover most of what you'll see. Do a lot of practice tests with a partner. The information is mostly simple; learning how to apply it and finish several case studies within an hour is the more difficult part.

Principles of Epidemiology in Public Health Practice is a self-study course released by the CDC that covers all major epidemiological and Disease Detectives concepts and includes a number of examples and sample cases. The full text is available online and in book form, and it is an excellent resource for learning the basic concepts in investigating an outbreak and finding new concepts that require additional research and study. Check it out!

after hours of searching, i still cannot find a good website on different kinds of infectious agent/disease causing agents, such as different vectors. Any suggestions?

Did you try the American Cancer Society website? They have good resources on specific infectious agents and their epidemiological implications.

I just tried searching for infectious agents on ACS, but it's all about cancer related specific diseases. i'm suppose to be looking for more general categories i think.