1L jobs - almost everyone i know got a job this summer, but because of the economy, only a few of them have firm jobs. If you really want a firm job you can get one, but it may be in a small market. Having a science degree could help, because of the IP/patent uses, but it comes in handy (and makes you more in demand) more during 2L OCI.
I'm working for a federal district judge this summer. I sent out approx. 100 resumes and cover letters to my hometown market and to the city I went to school in, and got 3 interviews. However, I got 2 offers out of 3 interviews, and the third one I didn't wait to hear back from before accepting my current job.
Don't worry about jobs though, worry about getting good grades first semester. I sent out my cover letters on the first day we were allowed to do so. If you can spare the time, I'd recommend doing that. I think it genuinely helps to be one of the first letters cross the desk in some of these judge's chambers.