First off, my advice is to look through the museum L archives as this question
comes up quite frequently.  Are you looking for an internship or an actual job
after graduation?  There are several websites out there that list one or the
other.. or in some cases both.  I have a lot of them bookmarked, if you would
like their URLs email me directly and I will see what I can do.  :)

You should be able to find these by doing a search in the meantime though:
MERC (museum employment resource center), America's JOB BANK, USAJOBS (federal
jobs), Opportunity NOCs, and many many others.

Feel free to email me and ask for the URLs of the several others I have
bookmarked!

Good Luck,
   Ginger M. Young