If it's something you need regularly I strongly suggest looking for someone locally. It's easy to find a research assistant but much harder to find someone who

If it's something you need regularly I strongly suggest looking for someone locally. It's easy to find a research assistant but much harder to find someone who will take intuitive leaps and search out stuff that you didn't know you wanted. If you are working in a specific field you should try finding a University in your area and e-mailing the head of that dept. That said, before I developed a relationship with the guy I use I generally had good luck with Guru.com