I graduated a month ago in December 08. It's weird because some companies will only be hiring for May grads in the spring but other companies will be done hiring December grads in the fall and working on the following May grads.
What seemed to work for me was to go to the school career fair, company events, etc. ASAP and start getting contacts and get your name out there.
Personally, I found my employer at a career fair about 3-4 months before graduation. I continued to interview with multiple other companies through September and October and had the job locked down by November. I ended up taking the very first offer I got
Overall, though, there really is no time too early to start. Some companies will prefer for you to go through the new grad hiring process in the Spring with the May grads. So yeah the best way to find out is to ask particular companies. Big companies will have HR individuals whose entire job is to deal with the college grad hiring process. If your school has a career center and/or career counselors they could probably offer you some contacts with those sorts of people.
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