Hi Satchi, for science and social science you should go to the ISI Web of Knowledge website. Go to "additional resources" then "journal citation reports". You can then select a certain field or topic, and it will show the list of journals ranked by various metrics, including the impact factor, which is what most people go by. Or if you already know of some journals, you can usually find their impact factors by googling or looking on each journal websites. Hope this helps.