The Science and Engineering Library is located in the East Wing of the Geisel Library, UCSD's central library building. Upon entering the Geisel Library, turn right and follow the signs to the S&E Library. The UCSD Libraries are open to the public.
Buses 30, 41, 48/49, 101, 150, and 921 all go through UCSD. The Gilman/Myers stop is closest to Geisel Library. You can also use the San Diego MTS trip planner (choose University of California, San Diego from the list of landmarks).