(1) conference rankings
(1.1) Google Scholar offers conference rankings in various fields, e.g., the rankings of conferences and journals in the Computational Linguistics field could be found here (other fields could be found on the left category tree)(1.2) Microsoft Academic Search also offers conference rankings in different fields, e.g., ranking of conferences in the Natural Language & Speech field could be found here.
(1.3) conference ranking in the Computer Science field could also be found on the Computing Research & Education Conference Portal
(2) journals
(2.1) free journal rankingsScimago Journal & Country Rank
(2.2) non-free ones
Thomson Reuters Journal Citation Reports® (most of the universities have this)