Labs love to have people who just finished school with a biology related degree. They also like people who have prior research experience (ie with their own independent research project, usually during their undergraduate career), or someone who is well versed in the techniques specific to the certain type of research that they do. Do you have research experience? References from professors? These are the types of things that people look for when hiring. If you want to look in the US, google several universities that have med centers, for instance Harvard, Johns Hopkins, etc. In your google search, include the phrase "employment opportunities," and you should usually find a webpage that allows you to browse through current openings at the respective institutions. Or you can do a more in-depth search, and browse for faculty members conducting research in field that interests you. You can contact these people with and email (including your CV, references...) although they might not be hiring. In terms of excatly where to look, the standard of research throughout the country (from the east to west coast) is very high, so you wont be at a loss which ever city you choose.
Getting a work permit might be hard, although I'm not sure b/c I've never looked into something like that, so don't quote me. But finding a research position, if you are willing to volunteer, shouldn't be too hard. I don't know about your financial situation, so not getting paid might be out of the question.
Good luck, I'm sure you will find something!
