Includes two sources
We hold these sources in print, but they have been digitized by the Federal Reserve Bank of St. Louis and are freely available in their FRASER database.
Virtually all of the sources here present nominal exchange rates, meaning they only the rate at which currencies exchange, ie 1$ = .75£. Real exchange rates are adjusted for inflation and other differences in prices. More information can be found in this article from the International Monetary Fund (121k PDF)
The IMF is the only online source available at the University of Chicago for time series data on real exchange rates.
You can also find information on other countries in books and articles.
Find books in the library catalog . Use the subject browse to look for "Banks and banking your country name Statistics" or "Finance your country name Statistics". This will find current as well as historical statistics
Articles in databases are other sources for finding information. EconLit is the best starting point as it includes many empirical studies on currency and foreign exchange. Use the descriptors field in the advanced search to look for foreign exchange or exchange rates. Narrow these results with keywords for countries of interest.